Smart Contract Development Cost: How to Estimate and Control It

A Practical Playbook for 2025 Budgets

When it comes to budgeting for 2025, especially with smart contracts, it's all about understanding what really drives those costs. In this guide, we’ll break down how to forecast expenses using solid inputs such as personnel time, audits, infrastructure, and gas fees. Plus, we’ll explore the latest strategies you can use after Dencun to manage your spending without compromising on security.

Understanding Smart Contract Costs

Smart contract costs can feel a bit overwhelming, but they come down to a few key factors:

• People Time: How much time your team spends on development and maintenance. The more complex the project, the more time you’ll need.
• Audits: Ensuring your contracts are secure is crucial. Budgeting for thorough audits is non-negotiable. Don’t skimp on this!
• Infrastructure: This covers everything from servers to the platforms you use for deployment. Reliable infrastructure can save you a lot of headaches down the line.
• Gas Fees: These are the costs associated with executing transactions on the blockchain. Keep an eye on these as they can vary.

Forecasting Costs with Concrete Inputs

To get a handle on your budget, use these concrete inputs:

1. Break down the project phases: Know how long each phase will take, and estimate personnel time accordingly.
2. Plan for audits early: Factor in the time and resources needed for thorough audits from the get-go.
3. Evaluate your infrastructure needs: Make sure you have a clear picture of what’s necessary to support your smart contracts.
4. Monitor gas prices: Keep an eye on trends in gas fees so you can adjust your budget and avoid surprises.

New Levers Post-Dencun

After Dencun, there are some fresh strategies you can employ to keep your spending in check while still ensuring robust security. Here are a few ideas:

• Optimized Gas Usage: Look for ways to minimize gas costs without sacrificing functionality.
• Automated Tools: Consider using automated testing tools that can save time and reduce the need for extensive manual work.
• Ongoing Education: Invest in training for your team to stay updated on best practices and emerging tools that can streamline processes.
• Collaborative Audits: Team up with other projects for group audits to share costs while maintaining high security standards.

By being proactive and strategic about these elements, you can navigate the budgeting landscape for 2025 and keep your smart contract costs under control. Remember, it’s about balancing budget with security, so you don’t have to sacrifice one for the other!

Summary for Description

By 2025, the biggest changes in smart contract budgets are largely driven by security (think audit mix and lead times), the choice of blockchain (especially after those post‑EIP‑4844 Layer 2 fees), and how productive developers can be. This guide offers decision-makers a solid cost model, new benchmarks to work with, and the most up-to-date control levers to help cut costs without increasing risk.

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1) Why cost discipline matters more in 2025

• Losses from web3 hacks and scams are still a big deal: According to Immunefi and other sources, losses are hitting the hundreds of millions each quarter in 2025. Just in Q3, they reported around $413M lost across 34 incidents, while some trackers estimated losses for the first half of 2025 to be close to $2.5B. Even though these numbers are lower than the peaks we saw in 2023 and 2024, it’s still a major risk that needs attention at the board level. So, it’s wise to budget for audits, bounties, and ongoing monitoring. (theblock.co)
• Bug bounties are officially a must-have in security budgets: Immunefi has paid out over $100M to researchers, and some top programs are offering massive rewards for critical findings--like Wormhole, which can go up to $5M. While the spending on bounties is relatively small compared to the risks they're helping to avoid, it’s definitely something you want to plan for early on. (theblock.co)
• After Dencun, Layer-2 execution costs took a turn: With EIP-4844 coming into play, we saw the introduction of “blob” transactions and a new fee market, which has slashed rollup data costs by over 90% in many instances. This can really help you lower your per-user costs--especially if you design your architecture with L2 in mind from the start. (blog.ethereum.org)

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2) The five cost pillars (and how to estimate each)

Think of it like this: there are five main buckets, and each one has different levers you can pull.

1. Product Scope and Protocol Complexity
   • Drivers: This includes the number of contracts, any external integrations like oracles, DEXs, and bridges, how upgradeable the system is, and which chains are supported.
   • Practical proxy: Think of it as source lines of code (SLOC) multiplied by a “risk weight.” A basic ERC‑20 or ERC‑721 token with roles is on the low end, while lending protocols, AMMs, RWA vaults, and cross‑chain messaging tend to be on the higher side.

2) Engineering Time (Build + Test)

• Looking ahead to 2025, if you're hiring in the US, here are some benchmarks to keep in mind: Solidity developers tend to pull in about $98k-$114k at startups, especially if you're based in NYC where it's usually even higher. For senior positions, you're often looking at salaries over $150k. If you're considering freelancers, their rates typically span from around $80 to $250 per hour. Just a heads-up, these figures don’t include all the extra employer costs, but they’re still super helpful for turning your sprint plans into real budget numbers. (wellfound.com)

3) Security (audits, re-audits, contests, bounties, monitoring)

• When it comes to security, looking at Tier-1 retainers on-chain can really help set our expectations. For example, OpenZeppelin’s 2023 Venus proposal listed 24 “research weeks” at a total of $554,400, which breaks down to about $23.1k per week or roughly $577 an hour if you’re putting in a full 40-hour work week. Then there's a 2025 thread on the Compound forum that mentions single reviews costing six figures.
• If you're into competitive audits, check out the prize pools offered by Code4rena and Sherlock, which typically range from $35k to over $235k. Some of their bigger contests have prizes that soar between $150k and a whopping $2M. You can dive into more details here: (community.venus.io).

4) Infrastructure (RPC, nodes, relayers, monitoring)

• RPC: Infura offers a pretty flexible pricing structure. You can get started for free, but there’s a daily credit cap. If you’re looking for more, they have plans at $50/month for developers and $225/month for teams, plus options for volume add-ons. Other providers like QuickNode and Chainstack have different pricing methods that depend on how you mix your requests and handle spikes. Check it out on their pricing page.
• Ops/monitoring: Just a heads up, OpenZeppelin is planning to phase out their hosted Defender SaaS by July 1, 2026. They’re shifting the Relayer and Monitor services to an open-source model, which means some costs will move from SaaS to DevOps. On the flip side, Forta’s detection network is pretty cool, offering a new "Firewall" for pre-transaction protection against common issues like reentrancy and oracle abuse. Using these tools can really help reduce incident costs if you implement them right. For more details, check out the OpenZeppelin blog.

1. On-chain costs (deployment + usage)
   • After EIP-1559, the formula is still “gas used × (base fee + tip)” on Layer 1. But with Dencun, Layer 2 data availability costs are moving to blob fees, complete with their own base fee market. This often means that L2-first setups can be a lot more cost-effective for high-volume read and write operations. (ethereum.org)

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3) A concrete estimation model you can use this week

Here’s a simple but effective process we follow with our product and finance teams:

• Step 1: Map your scope to a “risk-weighted SLOC” baseline
  • Minimal token + roles: 1× (low risk)
  • Vault (ERC‑4626) or staking with access control and pausing: 2×
  • Lending/AMM with custom math and liquidations: 3-4×
  • Cross‑chain messaging/bridge: 4-5×
    To help reduce those multipliers, stick to standards like ERC‑4626 for vaults. Incorporating ERC‑7540 async flows and ERC‑7575 for multi-asset setups can help cut down on custom code and integration risks. Check it out on (ethereum.org).
• Step 2: Convert to engineering weeks
  • A good rule of thumb is to plan for about 1 to 1.5 engineer-weeks for every 250 to 400 SLOC of Solidity that meets audited-quality standards. This includes everything--tests, fuzzing, invariants, and documentation. Don't forget to tack on an extra 25 to 50% for things like integration glue (think oracles and routers) and multi-chain deployments. Just remember to adjust this based on how fast your team works!
• Step 3: Choose a security strategy early on (it's all about mixing it up, rather than sticking to just one approach)
  • Here’s a solid combo for 2025 that tends to work well:
    • Start with one internal security sprint, covering the essentials like threat modeling, Slither, Foundry fuzz/invariants, and Scribble specs.
    • Follow that up with an external manual review, ideally getting 2-3 auditors for a scope of 1-3 weeks--or consider a retainer if that suits you better.
    • If you're involved in DeFi, look into a competitive audit lasting 7-21 days, with a budget ranging from $35k to $200k. Don't forget to plan for a re-audit afterward.
    • And, of course, set up a standing bug bounty with a decent critical max--think six or seven figures based on your total value locked (TVL). (github.com)
• Step 4: Infrastructure and Monitoring
  • Kick things off with a paid RPC tier that matches your Daily Active Users (DAU) and burst patterns; aim for about 2× headroom. Set up on-chain monitors and safeguards, like Forta detectors and anomaly alerts. If you’re using Defender right now, it’s a good idea to start planning for that 2026 migration to a self-hosted Relayer/Monitor or other alternatives. Check out more info on this here.
• Step 5: On-chain fee budget
  • Go with L2-first unless there's a solid reason to stick with L1. Thanks to EIP-4844, many L2 fees have plummeted by about 95-99% compared to the days before Dencun. Sure, you'll still have to cover the L1 base fee for batch transaction execution and the blob fee, but your costs per user are definitely a lot lower now. (cointelegraph.com)

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4) What things cost in practice (fresh benchmarks)

• Engineering talent
  • In 2025, if you’re looking at US startups, salaries for Solidity developers are typically in the ballpark of about $98k to $114k (that’s the median), but if you’re aiming for the best of the best, you might find some openings offering over $150k. Location really plays a role here too; for instance, in NYC, you can expect salaries to hover around $136k. If you’re thinking about hiring freelance experts, their rates generally range from $80 to $250 an hour, depending on their specialty, like audits, zk, or Move/Rust. Keep these figures in mind when you're translating sprint plans into your budget. (wellfound.com)
• Security reviews
  • Retainers: Let’s talk about an on-chain example--OpenZeppelin's security research costs about $554,400 for 24 weeks of work, which breaks down to roughly $23.1k a week. This kind of setup is pretty handy for figuring out "continuous audit" models, especially for protocols that are constantly evolving. If you check out the forum budgets, you'll see that some blue-chip DAOs are putting aside six-figure sums for each review. (community.venus.io)
  • Competitive audits: For a bit of fun, Code4rena and Sherlock offer prize pools that range from around $37.5k to over $235k; some of the big-name contests can even hit between $150k and $2M. These audits are often quicker to set up than your traditional Tier-1 slots and are great for uncovering a variety of issues. (github.com)
  • Lead times: Traditionally, companies would say it takes about 6-9 months to land an audit slot, which is where Diligence’s TURN token comes into play. This ERC-721 token represents 40 hours of auditor time and is meant for auctioning off time slots to skip the waitlists. If you're eyeing an audit, be prepared to wait a few weeks to months unless you get your plans in order early. (consensys.io)
• Bug Bounties
  • Immunefi has hit an impressive milestone--over $100 million paid to researchers so far! Some of the top programs, like Wormhole, offer critical payouts that can reach into the millions. They're often looking at around 10% of the funds at risk with specific caps for each program. Lately, it’s becoming more standard to set aside about 0.5-2% of Total Value Locked (TVL) or of the at-risk treasury for these bounties. You can check out more details over at theblock.co.
• Infrastructure
  • RPC/API: Infura has a Developer plan for $50/month, and a Team plan for $225/month that comes with daily credit limits. They also offer a custom plan for enterprises. You’ll find similar tiers with other providers, so it’s a good idea to compare method-weighted units and RPS caps to dodge any surprises. (infura.io)
• Monitoring and Incident Response
  • Forta’s network has got your back with both pre- and post-transaction threat detection. Their public reports highlight that for certain detector classes, the “time to detection” averages out to under 16 minutes. That’s quick enough to hit the pause button or set off circuit breakers if you set things up right. (forta.org)

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5) Post‑Dencun economics: modeling gas and fees the new way

• The math for L1 gas is still the same (EIP‑1559): Fee = gasUsed × (baseFee + priorityFee). Check out Ethereum.org’s guide to keep your budgeting in check. (ethereum.org)
• L2 data availability is now using blob space (EIP‑4844):
  • Each blob's 128 KiB in size, and the blob base fee works like EIP‑1559, aiming for around 3 blobs per block (with a max of 6). These blobs hang around for about 18 days before they get pruned, which is why they can be cheaper than calldata. This is a big reason why L2 fees dropped significantly after March 13, 2024. (blog.ethereum.org)
• Here are some practical budgeting tips:
  • Always start with L2 for user flows (Base, OP Stack, Arbitrum, zkEVM, Starknet), and only go to L1 for settlements or those rare special cases. Keep an eye on blob fee volatility if your usage tends to spike; most weeks, blob markets are pretty stable at their lowest, but it's good to prepare for those occasional spikes. (cointelegraph.com)

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6) Toolchain choices that lower cost without raising risk

• Testing and analysis defaults for 2025
  • For unit tests, property tests, and invariant testing, we're using Foundry (think forge/anvil). Plus, we're integrating gas reporting and fuzzing right into our CI process. Check it out here: (github.com)
  • For static analysis, Slither is our go-to; we're also using Echidna for fuzzing. And we're adding Scribble to help encode properties as executable specs. This really boosts auditor efficiency and cuts down on re-audit time. More details here: (github.com)
  • On the verification front, Hardhat’s verify plugin is a lifesaver--it supports Etherscan, Blockscout, and Sourcify, making it easier to catch any mismatches before we hit a block explorer. This can save engineers countless hours with every deployment! Check it out: (hardhat.org)
• Gas‑aware coding patterns (small tweaks, big savings)
  • Go for custom errors instead of revert strings (if you’re using Solidity ≥0.8.4). This helps reduce your bytecode size and cut down on revert costs. Also, consider using storage packing and unchecked increments in those hot loops, and try to steer clear of unnecessary event fields. These are straightforward pull requests that can help trim down both deployment and runtime expenses when you're scaling. (soliditylang.org)
• Upgrade patterns that trim down deployment gas
  • Go for UUPS proxies instead of Transparent proxies to keep proxy deployment costs low; stick to minimal clones (EIP‑1167) for your mass factory designs. Check out the guidance from OZ Contracts 5.x if you need beacons or clones. (docs.openzeppelin.com)
• Monitoring and Ops
  • Start planning your Defender migration since it's sunsetting on July 1, 2026. Take some time to weigh the pros and cons of using a self-hosted Relayer/Monitor versus going with third-party options. Don't forget to set up Forta detectors or similar protective measures for any oracle or reentrancy hotspots. A little investment in DevOps time now can save you from costly emergencies later on. (blog.openzeppelin.com)

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7) Standards that reduce build and audit scope (and save money)

• With ERC‑4626 for vaults (along with ERC‑7540 for async operations and ERC‑7575 for multi‑asset handling), you can cut down on custom vault code significantly and open the door to more integrations. Auditors will appreciate knowing the “happy path,” which helps speed up their review processes. (ethereum.org)
• The introduction of ERC‑2771 (meta‑tx) and EIP‑712 (typed data signing) is a game changer for user experience. They make gas fees and signature management easier to predict, and because everything’s standardized, there are fewer custom security issues to worry about. (eips.ethereum.org)
• Need to handle compliance? No problem! ERC‑3643 (T‑REX) and ERC‑1404 let you perform KYC/eligibility checks right on-chain. They also standardize pre‑transfer validations, which helps you avoid those messy, one-off implementations that can really complicate audits. (ercs.ethereum.org)

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8) Sample, numbers‑first budget breakdowns

Here are some reference mixes to assist you with calibration. Feel free to swap in your own inputs after you've assessed the SLOC and any associated risks.

• “Simple but serious” (think ERC‑20 with permit + timelock + pausable treasury)
  • Build: Expect around 2-4 weeks with a couple of engineers on board.
  • Security: Plan for 1 internal security sprint plus 1 light external audit (this will take about 1-2 weeks), or you could go for a contest that runs from $35k to $75k.
  • Infra: Budget around $50-$225 per month for RPC when you kick things off; you’ll want some basic monitoring in place too.
  • On‑chain: Deploy on L2; let’s keep Layer 1 focused on governance. (infura.io)
• “Vault or staking” (ERC‑4626 with guards + allowlists, multi‑chain L2)
  • Build: Expect to spend about 6-10 weeks with your engineering team (this includes tests, fuzzing, and invariants; using Foundry + Scribble).
  • Security: Plan for around 2-3 weeks with auditors or consider a mixed approach (some manual checks + a contest costing between $75k-$150k) plus a re-audit afterward.
  • Infra: Budget around $225 to $1k per month for RPC & alerting; don’t forget to set up Forta detectors for monitoring flows with pause switches. (diligence.consensys.io)
• “DeFi protocol v1” (think lending/AMM or cross‑chain messaging)
  • Build: Expect around 12-20+ engineer-weeks for this one, especially since it involves heavy invariants and simulating stuff.
  • Security: You’ll need a good retainer time or multiple audits--aiming for about 6+ auditor-weeks. Also, consider setting aside $150k-$300k for a contest, plus a continuous bounty with a solid critical cap based on TVL.
  • Infra: Be ready for some serious RPC spend if you’re transitioning from team to enterprise. Make sure you’ve got 24/7 monitoring along with incident runbooks handy. And don’t forget to leverage L2-first economics after EIP-4844 to keep those unit costs in check. (community.venus.io)

Note: These are just planning anchors. Make sure to connect your forecasts with your own test coverage metrics, source lines of code (SLOC), and risk profile.

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9) How to actively control (not just predict) cost

• Lock scope with interfaces and standards: Start by using OpenZeppelin along with ERC‑4626/2771/712 where it makes sense. Go for UUPS to keep things upgradable, which helps save on proxy gas and makes admin tasks easier. Remember, auditors really appreciate predictability. (docs.openzeppelin.com)
• “Shift‑left” security: Integrate tools like Slither, Echidna/Foundry fuzzing, and some Scribble properties into your “definition of done.” Catching issues before the audit not only saves you money but also reduces re-work. (github.com)
• Choose the right audit buying model per milestone:
  • Retainer: Best for protocols that are moving quickly and need steady, predictable capacity.
  • Fixed‑scope manual review: Helps reduce risk for a release candidate.
  • Contest: Great for gaining adversarial insights. Also, make sure to set aside some budget for a re‑audit window. For significant launches, consider using all three approaches. (community.venus.io)
• Exploit 4844 economics: Shift high-frequency user interactions to L2 and treat L1 as your settlement layer. Don’t forget to review your fee assumptions every quarter since blob markets are constantly changing. (blog.ethereum.org)
• Plan for ops realities: Keep in mind that Defender’s hosted shutdown in 2026 means you’ll want to budget some DevOps for self-hosting relayers and monitors, or consider a managed alternative in your 2025-2026 plans. (blog.openzeppelin.com)

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10) A worked example (numbers you can sanity‑check)

Scenario: Shipping an ERC‑4626‑Based Yield Vault on Base

Okay, so you’re gearing up to get an ERC‑4626-based yield vault out there on Base, and you have some cool features in mind. Let’s break it down!

Key Features

1. Pause/Guardian Roles
   You’ll want to set up some pause functionality and designate guardian roles. This means you can temporarily halt operations if something goes sideways, giving you a safety net.
2. Allowlist Deposits
   Implementing allowlist deposits is a great way to keep things secure. You can control who gets to invest in your vault, ensuring that only trusted users can contribute.
3. EIP‑712 Signed Operations
   Using EIP‑712 for signed operations is all about ensuring that the transactions are legit. This protocol helps you sign messages in a way that’s both human-readable and machine-verifiable, making your vault more secure.
4. Meta-Transaction Support via ERC‑2771
   Adding meta-transaction support through ERC‑2771 means users don’t have to hold your native token to interact with your vault. This greatly enhances user experience, making it easier for everyone to jump in.

Implementation Steps

You’ll want to consider the following stages for a smooth rollout:

1. Define Your Smart Contracts
   Start by defining your smart contracts for the yield vault, including all the necessary features mentioned above.
2. Set Up the Guardian Mechanism
   Create the logic for your pause/guardian roles. This will involve checking who has the authority to pause the vault and resuming operations.
3. Create the Allowlist
   Develop a mechanism to manage the allowlist for deposits. This can be as simple as an array of approved addresses or something a bit more complex with role-based access.
4. Implement EIP‑712
   Make sure to implement EIP‑712 signing in your contract functions. You’ll need to create the message structure and ensure proper validation.
5. Integrate ERC‑2771
   Lastly, integrate ERC‑2771 to support meta-transactions. This involves setting up a relayer service that can handle transactions on behalf of users.

Conclusion

That’s pretty much the roadmap for launching your ERC‑4626-based yield vault on Base! With the pause/guardian features, allowlist controls, EIP‑712 signing, and meta-transaction capabilities, you’ll be well on your way to creating a secure and user-friendly vault experience. Just keep testing and iterating, and you’ll have a solid product in no time!

• Build: So, if you’ve got 2 senior engineers working for 6 weeks, you’re looking at a total of 12 engineer-weeks. If you price it out at around $120 to $180 per hour (blended), you’re talking roughly between $57k and $86k for implementation, testing, fuzzing, and documentation.
• Security:
  • For internal security, plan for a sprint that'll take about a week.
  • On the external side, you’ll need 2 auditor-weeks for a manual review, plus a re-audit costing anywhere from $70k to $130k, depending on the firm you choose. Alternatively, you could go for a 10-14 day contest costing around $75k to $125k.
  • As for bounties, you might want to cap critical vulnerabilities to around 10% of the protocol’s initial Total Value Locked (TVL), which could look like a cap at $250k. (github.com)
• Infra: Start off with the $225/month RPC tier, and don’t forget to add Forta detectors for monitoring price/oracle issues and pausing flows. If you’re currently using Defender, think about a migration plan. (infura.io)
• On-chain: After the Dencun update, L2 fees are typically below a cent for basic operations on many rollups, though actual costs do shift with the blob base fee. You can assume the per-user cost will be pretty minimal compared to L1. Just keep some budget handy for occasional L1 governance or settlement transactions. (cointelegraph.com)

The total budget envelope for v1 that you can present to the CFO is in the low six-figure range. This will cover a production-grade, audited L2 vault that has a solid security posture.

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11) Quick checklist (print this)

• Requirements
  • Standardize on: OZ, ERC‑4626 (plus 7540/7575 if necessary), EIP‑712, ERC‑2771. (ethereum.org)
  • Opt for UUPS proxy if you’re going with an upgradeable setup. (docs.openzeppelin.com)
• Build pipeline
  • Run Foundry tests and generate a gas report; use Slither for static analysis; do some Echidna fuzzing; and create 2-3 Scribble properties to cover critical invariants. (github.com)
  • Set up Hardhat verification in the CI for explorers. (hardhat.org)
• Security Plan
  • Threat model document is ready.
  • External manual review is scheduled early (or we've got retainer time set aside).
  • Contest is lined up for adversarial breadth; we’ve blocked off a re-audit window. (github.com)
  • Bug bounty is live and there's a solid critical cap in place. (theblock.co)
• Ops and monitoring
  • Make sure the RPC plan has 2× headroom.
  • Connect Forta/guards to pause switches and have an incident runbook ready. (theblock.co)
  • Prepare a strategy for transitioning away from Defender (like a self-hosted relayer/monitor or another option). (blog.openzeppelin.com)
• Economics
  • Focus on L2-first for user flows; keep an eye on the blob market; and regularly adjust the pricing for per-user unit economics. (blog.ethereum.org)

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Closing thought

In 2025, when you're looking at your smart contract “budget swing,” it's less about day-rate coding and more about having a solid security strategy. You'll want to figure out your position on the L1/L2 spectrum after EIP-4844. Here are four key things you should focus on:

1. Standardize aggressively.
2. Shift-left on security.
3. Invest in the right mix of audits for each milestone.
4. Move your high-frequency flows to L2.

Nail these, and you'll not only ship faster and spend less, but you'll also seriously cut down on tail risk.

If you're looking for a quick, numbers-focused estimate tailored to your needs, 7Block Labs is ready to help! Just share your requirements and repos with us, and we can whip up a calibrated budget scenario (covering build, security, infrastructure, and on-chain) in no time.