Product development cost: a practical guide to budgeting mobile apps and SaaS platforms

A validated product scope typically costs €9.5k–€15k to define. A production-ready mobile app, website or SaaS platform typically costs €38k–€120k to build, depending on scope. Ongoing improvement runs as a monthly retainer. Numbers below explain why.

Software pricing is rarely about lines of code. It is about the time of experienced people making decisions you will live with for years. Five cost drivers explain most of the variance:

• Scope clarity. A vague scope is the most expensive thing in software. Every undecided detail becomes a meeting, a rework, or a bug.
• Surface. A mobile app, a marketing website and a SaaS platform have different performance, security and platform-store constraints.
• Integrations. Payments, auth, CRM, billing, analytics — each one is a contract with an external system that has to be tested, monitored and maintained.
• Compliance. GDPR, accessibility (WCAG), App Store and Play Store review, SOC-style hygiene for B2B SaaS. These are non-negotiable and they take time.
• Ownership. A product you fully own — source code, infrastructure, documentation — costs slightly more upfront and dramatically less over five years.

Primisia structures engagements around two clear scopes. They are sequential, not alternatives.

For teams already shipping, an Embedded monthly retainer keeps a forward-deployed engineer close to the product — typically quarterly engagements priced on capacity, not on tickets.

Ranges assume a single, focused product — not a platform of products. Reproducing a Notion or a Shopify is not a budget, it is a company.

• Skipping the sprint. Building before the scope is validated is the most common reason projects double in cost.
• Treating design as decoration. Visual polish is cheap; product decisions made in Figma are expensive to change in code.
• Proprietary runtimes. Low-code lock-in feels cheap until migration day.
• Vague acceptance criteria. "It should be fast" is not a target; "LCP under 2s on 4G" is.
• Outsourced QA bolted on at the end. Quality is a budget line from week one, not a final-week sprint.

Initial build is roughly 30–40% of a product's five-year cost. The rest is hosting, third-party services, support, and continuous improvement. Three levers control TCO:

• Performance budgets enforced from day one — LCP under 2s, INP under 200ms, CLS under 0.05.
• Portable infrastructure — standard frameworks, documented runbooks, no proprietary runtime.
• Source-code ownership — delivered via Git from week one, no escrow, no hostage data.

1. State the business outcome, not the feature list ("reduce no-shows by 30%", not "add a calendar").
2. Name the one number that has to move. Every other feature is in service of it.
3. List integrations and constraints (payment provider, CRM, languages, regulated industry).
4. Share the deadline that actually matters and why.
5. Be honest about the budget envelope. A studio can right-size scope to a budget; it cannot guess.

A Product Sprint ends with a fixed-price quote for the build. No surprises after sign-off, source code delivered to you, infrastructure of your choosing.