A simple web app with a database, user accounts, and a few core screens typically costs $5,000–$20,000 to build. A production SaaS product with billing, multi-tenant data isolation, and an admin panel runs $20,000–$80,000+, depending on scope. The single biggest cost driver is not the technology — it is who builds it and where they are based. A solo developer in the Balkans can ship the same feature set as a Western European agency for a fraction of the rate, often in less calendar time.
This is the budgeting hub for everything cost-related on this site. It explains how software pricing actually works, what you are paying for, and why two quotes for "the same app" can differ by 5x. If you want to plug numbers into a calculator instead of reading, use the app cost estimator — but read this first so the estimate makes sense.
Key takeaways
- Web app: $5,000–$20,000 for a database-backed app with auth and a handful of screens. A marketing/brochure site is far cheaper — see the website development cost breakdown for that tier.
- SaaS product: $20,000–$80,000+ once you add subscription billing, multi-tenancy, role-based access, and an admin panel. The SaaS MVP development guide covers what belongs in v1 versus v2.
- The rate, not the stack, drives the number. A Balkan solo developer and a London agency can use identical tools and quote 4–6x apart.
- Pricing models matter: fixed-scope, hourly, and retainer each fit a different stage of certainty. Pick the wrong one and you overpay or under-deliver.
- Hidden costs are real: payment integration, security/compliance, infrastructure, and post-launch maintenance routinely add 20–40% to the headline build number.
- Faster is cheaper. When one developer can ship in about 10 weeks what a team coordinates over four-plus months, you pay for fewer hours and less overhead.
How much does it cost to build a web app?
The honest answer is a range, because "web app" describes everything from a single-form lead capture tool to a logistics dashboard with live data. To make the number useful, break the build into tiers.
Tier 1 — Simple web app ($5,000–$12,000). User accounts, a database, CRUD screens (create/read/update/delete records), basic search and filtering, email notifications. Think an internal tool, a booking form with an admin view, or a directory. One developer can build this in roughly 3–5 weeks.
Tier 2 — Mid-complexity web app ($12,000–$25,000). Everything in Tier 1 plus third-party integrations (payments, maps, calendars), file uploads, multi-language support, and a more designed front end. Pizzeria Bestek sits here — a React + Supabase ordering app with four languages and a live menu, built solo. The integration and i18n work is what separates this tier from the first.
Tier 3 — Complex web app / early SaaS ($25,000–$50,000). Real-time features, per-user or per-tenant data separation, subscription billing, a back-office admin panel, and the testing discipline a paying product needs. This is the boundary where a "web app" becomes a "SaaS product," and the cost step-change comes from billing and data isolation, not from the UI.
If your project is closer to a content site or marketing presence than an application, the math is different and usually much lower — the dedicated cijena izrade web sajta 2025 guide breaks down site-tier pricing for the regional market.
What makes SaaS more expensive than a regular web app?
A SaaS product is not just "a web app you charge for." Three things add cost that a one-off web app never touches.
Billing and subscriptions. Charging once is easy. Charging every month — with trials, upgrades, downgrades, proration, failed-payment retries, and dunning emails — is a whole subsystem. Stripe handles the payment rails, but wiring webhooks correctly so your database always reflects the true subscription state is real engineering. The SaaS billing and payments guide covers what this actually involves. Budget for it as a feature, not a checkbox.
Multi-tenancy. When many customers share one application, each one's data must be invisible to the others. Getting this wrong is the most expensive bug in SaaS because it is a data breach, not a glitch. Callidus, a clinic SaaS built with React and Firebase, uses per-tenant Firestore security rules so one clinic can never read another's patient records — that isolation was a core part of the ten-week build, not an afterthought. The multi-tenant SaaS architecture guide explains the patterns and their cost implications.
Operations and trust. A SaaS that holds customer data needs audit trails, an admin panel to support users, background jobs, and a credible answer to security questions. The SaaS security and compliance guide and the backend infrastructure guide cover the parts buyers forget to budget for. These are not optional polish — they are why SaaS quotes start where web-app quotes end.
How do software pricing models work?
There are three common ways to pay for a build, and each fits a different level of certainty about scope.
Fixed-scope (fixed price). You agree on a defined feature set and a price up front. Best when the scope is genuinely clear — an MVP with a known feature list, a redesign, a well-specified internal tool. The risk shifts to the developer, so the quote includes a buffer. Change the scope mid-build and you renegotiate. This is the most common model for first projects because it caps your downside.
Hourly / time-and-materials. You pay for hours worked. Best when scope is exploratory or expected to evolve — R&D, an unclear MVP, or ongoing iteration where you want to steer week to week. Cheaper in theory if the work is efficient, but it requires trust and visible progress, because you carry the scope risk.
Retainer. A recurring monthly amount for a set capacity — maintenance, new features, support. Best after launch, when you have a live product that needs steady evolution rather than a one-time build. Predictable for both sides and the right model for a product that is alive, not finished.
For most founders the sequence is: fixed-scope for the MVP, then a retainer once it ships. Hourly fits the messy middle when you genuinely cannot specify v1 yet. The SaaS MVP development guide helps you scope tightly enough to make a fixed price viable in the first place.
Why do quotes for the same app differ by 5x?
When you get a $15,000 quote and an $80,000 quote for what sounds like the same product, the gap is almost never about quality. It is about three structural differences.
Rate and location. A developer's hourly rate is set by their local cost of living and market, not by the value of the code. Western European and US agency rates of $100–$200+/hour reflect overhead — sales teams, project managers, office space — layered on top of the engineer's time. A solo developer in Bosnia, Croatia, or Serbia working at $25–$60/hour delivers the same output without that overhead. Same feature, same stack, a fraction of the invoice.
Team overhead versus solo focus. An agency assigns a project manager, a designer, a front-end developer, and a back-end developer, then bills you for the meetings that keep them in sync. A solo full-stack developer who designs, builds the front end, and writes the back end has zero coordination overhead. That is why the same project ships faster than a typical agency when built solo than through a typical agency pipeline — fewer hours billed, less calendar time lost to handoffs.
AI-augmented workflow. Tooling has changed how fast a single developer can move. Repetitive scaffolding, boilerplate, and test generation that used to eat days now take hours. This does not replace engineering judgment — it removes the slow parts so the developer spends time on the decisions that actually matter. The AI-augmented development guide explains where this speeds things up and where it does not. The practical effect on your invoice: fewer hours for the same result.
The lesson is not "always go cheapest." It is that a high quote does not mean a better app, and a low quote does not mean a worse one. It means a different cost structure.
What does development cost in Bosnia, Croatia, and Serbia?
The Balkans is one of the strongest value markets in software right now: a deep pool of engineers trained on the same stacks as the West, working at a fraction of Western rates, with English fluency and overlapping time zones for European clients.
Typical solo developer rates in the region land around $25–$60/hour depending on experience and specialization, against $80–$150+/hour for comparable Western European freelancers and far more for agencies. The work product is not regional — React, Flutter, Firebase, Supabase, and Stripe are the same everywhere. What differs is the price.
Three real builds make this concrete. BookBed, a six-platform booking SaaS with bidirectional iCal sync, was built solo in six months on Flutter, Firebase, and Stripe — a scope a Western agency would have quoted as a multi-developer, multi-quarter engagement. Callidus, a clinic SaaS with per-tenant data isolation, shipped in about 10 weeks solo. Pizzeria Bestek delivered a four-language ordering app on React and Supabase. None of these required a team; all of them required focus.
The caveat regional buyers should weigh is invoicing and contracts, not capability. A solo developer may not run a registered company, so for clients who need a formal VAT invoice there are intermediary rails that issue compliant invoices on the developer's behalf. That is an administrative detail, not a quality signal — vet the work, not the letterhead.
If you are deciding between a solo developer, an agency, and an offshore team, the hiring SaaS developers guide walks through vetting, communication, and the trade-offs of each.
What hidden costs should you budget for?
The build quote is the headline, but it is not the whole bill. Plan for these or they will surprise you.
- Payment integration. Stripe takes roughly 2.9% + a fixed fee per transaction. Building and testing the billing flow is part of the dev cost; the per-transaction fee is a permanent line item once you are live.
- Infrastructure and hosting. Firebase, Supabase, Vercel, and similar platforms have generous free tiers, then scale with usage. A small product might run on $0–$50/month; growth pushes that up. Cheap to start, worth modeling for scale.
- Third-party services. Transactional email (Resend, Postmark), maps, SMS, error monitoring — each is a small recurring cost that adds up.
- Maintenance. Software is not a one-time purchase. Dependency updates, bug fixes, and small improvements typically run 15–25% of the original build cost per year. A retainer is how most products handle this.
- Design. If you do not have designs, that is a separate effort. A full-stack developer who also designs folds this in; otherwise budget for a designer.
- Growth and onboarding work. Getting users to activate and stay is its own investment after launch — the SaaS UX and growth guide covers what that takes.
A useful rule of thumb: take the build quote and add 20–40% for the first year to cover integration fees, infrastructure, and maintenance. That is your realistic total cost of ownership, not the sticker price.
How do you keep software costs under control?
The most expensive software is the software that gets rebuilt. A few decisions early save far more than haggling over the rate.
Scope ruthlessly. Every feature you defer is money saved now and optionality kept for later. Ship the smallest thing that delivers value, then let real usage tell you what to build next. The SaaS MVP guide is built around this discipline.
Pick the right pricing model for your certainty. Fixed-scope when you know what you want; hourly when you are still figuring it out; a retainer once it is live. Forcing a fixed price onto an undefined project produces either padding or scope fights.
Value speed and focus over headcount. More people on a project is more coordination cost, not automatically more output. A focused solo developer or a small, experienced team often beats a large agency on both cost and timeline.
Plan for maintenance from day one. Budgeting the retainer up front stops the "we shipped and now nobody owns it" decay that forces an expensive rebuild eighteen months later.
If you want a tailored number rather than a range, the app cost estimator turns your feature list into a budget, and the supporting website development cost guide and cijena izrade web sajta 2025 drill into the site-tier end of the spectrum. Whatever you build, the cost follows the same logic: scope, rate, and how efficiently it gets built — in that order.