This is probably the most asked, and least honestly answered, question in the startup ecosystem.
Online, you'll find absurdly wide ranges: "between $10,000 and $500,000." That's not an answer. It's a way of dodging the question.
👉 In this article, we break down the real cost drivers, realistic benchmarks, and what separates a well-budgeted project from one that spirals out of control.
Why estimates vary so much
Before the numbers, it's worth understanding why the question is so hard to answer. Three main reasons:
1. "SaaS" covers wildly different realities. An internal management tool for a small business, a multi-tenant B2B platform with a public API and SSO, and a two-sided marketplace have nothing in common in terms of complexity. Comparing their costs is like comparing a bicycle to a car because "both have wheels."
2. Your stack choice changes everything. Development costs depend on the technologies chosen, but even more on how well the team actually masters them. An exotic stack with a junior team can cost three times more than a standard stack with an experienced one.
3. Scope is rarely locked down upfront. Most projects aren't properly scoped before work begins. What starts as "a simple V1" frequently expands over the weeks, and the budget follows.
The real cost drivers
1) Functional complexity
This is the number-one factor. Here's what drives the budget up:
| Feature | Cost impact | Notes |
|---|---|---|
| Basic auth (email/password) | Low | Standard, fast to implement |
| SSO / OAuth (Google, Microsoft, etc.) | Medium | Requires a clean integration |
| Advanced roles and permissions | Medium to high | Complexity grows fast |
| Payments and subscriptions (Stripe, etc.) | Medium | Billing logic is often underestimated |
| Multi-tenancy with data isolation | High | A foundational architecture decision |
| Documented public API | High | Versioning, security, technical docs |
| Notifications (email, push, SMS) | Medium | Infrastructure + state management |
| Embedded reporting and analytics | High | Data complexity + UI often underestimated |
| Third-party integrations (Zapier, webhooks, etc.) | Variable | Depends on depth and volume |
| Generative AI (LLM, RAG, etc.) | High | Infra cost + product complexity |
👉 Every feature you add costs not just its development time: it also costs test time, integration time, and future maintenance.
2) The team model you choose
This is the second factor, often underestimated because people don't always compare the right things.
| Model | Indicative monthly cost | Advantages | Risks |
|---|---|---|---|
| Senior freelancer (France/Europe) | €600–900/day | Targeted expertise, responsiveness | Dependency, availability, turnover |
| Offshore agency | €3,000–15,000/month | Low headline cost | Variable quality, coordination overhead, frequent delays |
| France / Europe agency | €8,000–25,000/month | Quality + oversight + accountability | Higher cost |
| In-house team (2 devs + 1 PO) | €25,000–40,000/month | Deep domain knowledge | Long recruitment, fixed cost, turnover risk |
| Subscription model (like Inprogress) | €5,000–15,000/month | Flexibility + continuous execution | Requires solid upfront framing |
This table hides an important truth: the listed cost is never the real cost. An in-house team requires management, tooling, onboarding, paid leave, and replacement costs when someone leaves. An offshore agency requires a coordination overhead that's systematically underestimated.
3) The quality of your technical foundation
This is the invisible cost, the one that doesn't show up in the initial quote but gets paid for months or years afterward.
A V1 built fast without rigor can cost 30–50% less upfront, and twice as much in the long run, because every new feature becomes a major undertaking.
Warning signs of a poor technical foundation:
- simple features taking longer and longer to ship
- recurring bugs on flows that should be stable
- the app can't run without the original developer present
- no tests, no documentation, no observability
"The real cost of a bad technical foundation isn't the fix. It's everything you couldn't ship because of it."
4) The level of design work
Design is often the first budget cut, and it's usually a mistake.
A SaaS without serious UX work generates:
- a broken onboarding (users don't adopt the product)
- higher support costs (the interface isn't intuitive)
- higher churn (the experience doesn't make users want to come back)
Design isn't an aesthetic cost. It's an acquisition and retention cost.
Realistic benchmarks in 2026
Phase 1: MVP (Minimum Viable Product)
A well-built MVP addresses one precise value proposition, with the core user journey working, a solid technical foundation, and the ability to iterate.
Realistic range: €20,000 to €60,000
What drives variation within this range:
- number of user roles
- presence or absence of payments
- expected design quality
- data model complexity
⚠️ Below €20,000, be cautious. Either the scope is genuinely minimal, or serious quality compromises have been made. An MVP at €8,000 that needs a full rebuild in 6 months isn't cheap: it's a double cost.
Phase 2: Growing product (6–18 months post-launch)
This is where the SaaS evolves based on user feedback, adds new features, and needs to start scaling.
Realistic range: €8,000 to €20,000/month
This budget typically covers:
- continuous sprint execution
- backlog management and technical decision-making
- maintenance and stabilization
- regular feature development
Phase 3: Mature product with accelerated growth
At this stage, the SaaS has active users, significant ARR, and real scalability, security, and integration challenges.
Realistic range: €20,000 to €50,000/month (depending on team size and complexity)
The most common budgeting mistakes
Mistake 1: Thinking "build cost" instead of "total cost"
The initial development rarely represents more than 30–40% of the total cost of a SaaS over 3 years. Maintenance, new features, bug fixes, integrations, and scalability make up the rest.
Budget from the start on 12 to 18 months, not just the V1.
Mistake 2: Underestimating integrations
Integrations (CRM, payment tools, analytics, transactional emails, webhooks) are systematically underestimated. A "simple" Stripe integration can take 3 to 5 days when you factor in subscription state management, webhooks, refunds, and edge cases.
Mistake 3: Not including infrastructure costs
AWS, GCP, or Azure aren't free. At launch, infra costs are often negligible (€100–500/month). During growth, they can quickly exceed €2,000 to €10,000/month depending on traffic, data volume, and managed services.
Also anticipate: CDN, file storage, managed database, emailing services, monitoring, alerting.
Mistake 4: Forgetting the cost of poor scoping
A poorly scoped project costs more than a well-scoped one. Back-and-forth, mid-sprint scope changes, and functional misunderstandings have a real cost, often 20–30% of the total budget.
Investing 2 to 4 weeks in rigorous upfront scoping (structured backlog, validated journeys, defined architecture) isn't wasted money. It's protection against runaway scope.
Mistake 5: Choosing the cheapest option without calculating the risk
A quote that's 40% cheaper than another isn't necessarily a good deal. The question to ask isn't "how much does it cost?" but "what's the probability this project ships on time, with a usable result?"
A project that slips by 6 months carries an opportunity cost that often far exceeds the price difference between two providers.
Agency vs freelancer vs in-house: the real calculation
Many founders compare these options based on day rate or gross salary. That's not enough.
In-house team: the real cost
Two senior developers + one product owner in France:
- Gross salaries: ~€16,000/month
- Employer contributions (~45%): +€7,200/month
- Tooling (Jira, GitHub, Figma, etc.): ~€500/month
- Recruitment (one-time, but ~15–20% of annual salary): ~€12,000–18,000 per hire
- Management, onboarding, turnover risk: unquantifiable but real
Real total: €25,000 to €35,000/month, excluding the fixed costs during slow periods and the risk of losing a key person.
Agency: what you're actually buying
Beyond the rate, a good agency brings:
- a team that already works well together (no onboarding delay)
- processes already in place (backlog, sprints, reviews)
- risk coverage (sick leave, vacation, departure)
- contractual accountability
- multi-project experience (the mistakes have already been made elsewhere)
The right selection criterion isn't the rate: it's execution reliability and clarity of the collaboration framework.
How to estimate your project budget
A simple four-step method:
Step 1: Define the V1 scope List the features essential to launch. Not "nice to haves," not future ideas. The strict minimum to validate your value proposition with real users.
Step 2: Estimate the complexity of each block For each feature, assign a complexity: simple (1–3 days), medium (3–7 days), complex (7+ days). Multiply by your team model's day rate.
Step 3: Add risk buffers Add 20–30% for unforeseen issues, poorly estimated integrations, and inevitable functional back-and-forth.
Step 4: Project over 12 months Add the maintenance and evolution cost post-launch. A live product needs continuous execution capacity.
What this means for your fundraising
If you're preparing a funding round, your investors will look at how you manage your tech costs.
Typical questions:
- What is your monthly burn rate on tech?
- Do you have a clear plan for the next 12 months?
- What is the state of your technical foundation (debt, scalability, security)?
- Do you have quality metrics (bugs, time to deploy, test coverage)?
A founder who can answer these questions precisely reassures investors. A founder who says "we'll figure it out after the raise" raises red flags.
Summary: the numbers to remember
| Phase | Indicative budget | Recommended team model |
|---|---|---|
| MVP (0–3 months) | €20,000 – €60,000 | Agency or senior freelancer |
| Growth (6–18 months) | €8,000 – €20,000/month | Agency or subscription model |
| Scale (18+ months) | €20,000 – €50,000/month | Hybrid or reinforced in-house team |
The real question isn't "how much does it cost?" but "what's the return on every euro spent on development?"
A well-built SaaS that validates its market in 90 days is worth far more than a perfect SaaS delivered in 18 months.
👉 If you want to frame your project budget precisely, let's talk. 30 minutes is enough.