What actually drives SaaS MVP costs
MVP costs aren't determined by some magic formula. They're determined by scope. And scope is determined by answering these questions honestly:
- How many user roles? (admin only = simple, multiple roles with different permissions = complex)
- How much data does each user generate and retrieve? (Simple list = cheap, complex search/filtering = more expensive)
- How many integrations with other systems? (Zero = simple, Stripe + Salesforce + email = more complex)
- Real-time features or notifications? (Static page = simple, live updates = more complex)
- Custom design or template-based? (Template = cheaper, custom UI/UX = more expensive)
Your costs scale with each of these. Understanding your requirements on each axis helps you estimate realistically.
The anatomy of a SaaS MVP build: What costs what
| Component | Simple MVP | Standard MVP | Complex MVP |
|---|---|---|---|
| Discovery & Requirements | £1,000 | £2,000 | £3,000 |
| Design & UX | £2,000 | £4,000 | £8,000 |
| Backend Development | £4,000 | £8,000 | £15,000 |
| Frontend Development | £2,000 | £5,000 | £10,000 |
| Testing & QA | £1,000 | £2,000 | £4,000 |
| Deployment & Ops | £500 | £1,000 | £2,000 |
| Post-Launch Support (30 days) | £1,000 | £2,000 | £3,000 |
| TOTAL | £11,500 | £24,000 | £45,000 |
What counts as "Simple MVP" (£11K-15K)
- Single user type (no role-based access control)
- Core feature only (one main workflow that solves the core problem)
- Stripe payments (standard subscription, no custom billing logic)
- Basic admin dashboard (manage users, view stats)
- Template-based design (not custom UI)
- No integrations with external systems
- Email notifications only (no SMS, webhooks, etc.)
Example: A note-taking SaaS where users sign up, create notes, subscribe monthly. That's simple scope.
What counts as "Standard MVP" (£20K-35K)
- Multiple user roles (admin, member, viewer)
- Core feature + basic workflows (users create objects, edit, collaborate)
- Stripe payments + subscription management (plans, upgrades, cancellation)
- Custom design (branded, thoughtful UX, not template-based)
- Search and filtering (users can find their data)
- One external integration (Slack API, email provider, or basic Salesforce sync)
- In-app notifications, email digests
- Basic API for third-party access
Example: A project management tool where teams sign up, create projects, assign work, subscribe for monthly access. That's standard scope.
What counts as "Complex MVP" (£40K-70K+)
- Complex permission model (custom roles, granular access control)
- Multiple interconnected workflows (objects relate to each other in complex ways)
- Advanced payments (tiered pricing, usage-based billing, credit system)
- Real-time features (live collaboration, instant updates across users)
- Multiple integrations (Salesforce, NetSuite, Xero, custom systems)
- Custom reporting or data export
- Mobile app (native iOS/Android or responsive web counts as more work)
- Advanced API with webhooks and third-party authentication
Example: A financial compliance platform where teams manage regulatory requirements, track audit trails, export reports, and sync with accounting systems. That's complex.
Hidden costs that blow budgets
You likely didn't budget for...
- Security audits or penetration testing (£2K-5K) — Essential if you handle sensitive data or customer data.
- Infrastructure and hosting setup (£500-2K) — Database setup, SSL certificates, backups, monitoring.
- Mobile responsiveness testing (£1K-2K) — If you care about mobile UX (you should).
- Email delivery setup (£500-1K) — Getting off spam lists, setting up DKIM, SPF, DMARC.
- Analytics and monitoring (£500-1K) — Sentry for error tracking, Mixpanel or similar for product metrics.
- Compliance (SOC 2, GDPR) (£1K-3K) — If you're targeting enterprises or processing EU data.
- Figma to code handoff or design specs (£1K-2K) — Designers and developers working together adds overhead.
How to reduce costs without sacrificing quality
Scope aggressively
The single biggest cost reducer is ruthless scope cutting. Not features — scope. Features are the problem you solve. Scope is how polished it is, how many edge cases you handle, how many integrations you support.
- One integration instead of three saves you £4K-6K.
- Template design instead of custom UI saves you £2K-3K.
- No mobile app saves you £8K-15K (do responsive web instead).
- Basic permissions instead of complex roles saves you £2K-3K.
Use existing tools and platforms
Don't build what exists:
- Use Stripe for payments (don't build your own payment processing).
- Use SendGrid for email (don't roll your own email service).
- Use Auth0 for authentication (don't build user registration from scratch).
- Use Zapier for basic integrations (don't build custom API integrations immediately).
Use templates for design
Custom design is expensive and time-consuming. Figma templates or design systems let you ship with professional-looking UI without the cost. You can custom-design later when you have users.
Defer nice-to-haves
Anything that's not essential to the core user journey is deferred. Advanced reporting, detailed analytics, white-labeling, bulk operations, data export — all deferred.
How timeline and cost interact
Tighter timeline = higher cost. Hiring more developers accelerates build but costs more. You can't have both a cheap and fast MVP.
| Timeline | Standard MVP Cost | Note |
|---|---|---|
| 8-10 weeks (normal pace) | £20,000-25,000 | One developer, steady progress |
| 6-8 weeks (accelerated) | £25,000-35,000 | Two developers, more overhead |
| 4-6 weeks (rushed) | £35,000-50,000 | Multiple developers, quality suffers |
Don't forget: post-launch costs
Your build cost is not your total cost. After launch, budget for:
- Hosting: £50-500/month depending on load
- Third-party services: Stripe (2.2% + fee), SendGrid, Auth0, etc. (~£100-300/month)
- Bug fixes and support: £1,000-2,000/month for the first 3 months
- Feature development: Plan for this. One new feature per month = £2,000-4,000/month
Build vs buy decision: Before you spend £25K building, ask: does an existing tool solve 80% of this? Sometimes a customer already uses Asana, Notion, or Airtable and would use that instead of your product. Know your competition.
How to get an accurate cost estimate
- Do discovery with an agency (£1,000-2,000, 1-2 weeks): They'll ask detailed questions about your requirements and scope.
- Get a scoped proposal: Should clearly state what's included and what's not.
- Ask for task-level breakdown: A proposal that says "Backend: £8,000" is vague. "User registration system: £1,500, Dashboard: £2,000, etc." is clear.
- Buffer for unknowns: Even good estimates have 10-20% uncertainty. Build this in.
If you're getting wide-ranging estimates (£15K-50K), that means the scope isn't clear. Get more specific before committing.
