A $50,000 proposal lands in your inbox. Looks solid. You sign. Six months later you’re $120,000 in and the project still isn’t done.
This isn’t bad luck. It’s how software estimates work — or don’t.
Roughly one in six software projects doubles in cost. The average schedule runs 70% over. These aren’t outliers, they’re the statistical norm. The problem isn’t that agencies lie. It’s that the quote can only show you what they thought they knew at the time. Everything they didn’t know — integrations, platform complexity, post-launch reality — shows up later as an invoice.
The Five Things Your Quote Won’t Tell You
1. Integrations Are Never Simple
Your app talks to payment processors, email services, CRMs, authentication providers, analytics — and probably some legacy system nobody wants to mention.
Every integration has its own API quirks, auth dance, and data format. What looks like “Stripe: 1 day” in the quote turns into 3–5 once you account for webhooks, error handling, refund logic, and the edge cases that only show up in production. I’ve seen teams burn two weeks on a “simple” Salesforce sync.
Most first quotes estimate integrations at about half the real cost. Plan accordingly.
2. “Mobile App” Is Two Projects, Not One
iOS and Android together don’t cost 1.5x. They cost 2x. Different UI conventions, different navigation, different testing matrices, different deployment pipelines. Someone has to build and maintain both.
If a quote says “mobile app” without specifying platforms, that’s the biggest cost multiplier hiding in plain sight.
3. The Bill Doesn’t End at Launch
Development is the down payment. After launch you need:
- Hosting: $200–2,000/month depending on what you’re running
- Security patches and monitoring
- Database maintenance
- Bug fixes (there are always bugs)
- Third-party API fees that scale with usage
- Customer support tooling
These add 15–25% to your annual budget. If the quote doesn’t mention them, ask why.
4. Death by a Thousand Small Changes
Different button color. Extra field on a form. Reorder the dashboard. Each one is “small.” Individually they’re cheap. Collectively they eat 8–15% of your budget before anyone notices.
Without a formal change request process, you’re authorizing these every time you say “actually, could we also…”
5. Skipping Discovery Saves Money Today, Costs You Double Tomorrow
Discovery is the phase where the agency figures out what you actually need before writing code. Many quotes skip it because it’s an upfront cost the client doesn’t want to pay.
The problem is the assumptions made in a discovery-free quote always prove wrong. And when they do, you pay for discovery anyway — at full development rates. A $3,000–10,000 discovery phase can prevent 30–50% of budget overruns.
How to Read a Proposal Like Someone Who’s Been Burned
These are the six things I look for:
- Phase breakdown. One line item = danger. You want to see discovery, design, dev, QA, deploy, and maintenance separated.
- Integration detail. “Standard integrations” means “we haven’t thought about it.” Each integration should be called out with its own estimate.
- Platform specifics. “Mobile app” is not specific enough. You want iOS and Android priced separately.
- Revision limits. Not mentioned? You’re going to pay for every revision after the first batch.
- Change request process. If it’s not defined before you sign, it’ll be defined when it benefits the agency.
- Post-launch costs. If the quote stops at launch, the real cost hasn’t started yet.
Benchmarks Are Worth More Than Any Single Quote
If your project comes in at $50K and benchmarks for similar projects cluster around $40K–75K, you’re in the right zone. If benchmarks say $80K–150K, your $50K quote is missing something significant — probably several things.
Benchmarks won’t tell you which vendor to pick. But they’ll tell you when something is off, which is usually enough.
About Apropo
We built Apropo to make proposals transparent enough that this guide becomes unnecessary. When agencies use our tools, clients get itemized cost breakdowns, multiple scope options, risk buffers shown in the open, and change tracking that doesn’t disappear into a PDF.
I started the company because I kept watching people sign contracts that looked fine on paper and fell apart in execution. The gap between what the proposal shows and what the project costs is real, and the only fix is to show everything upfront.
Questions Worth Asking
Is this really that common? One in six projects doubles in cost. Those are the published numbers from the industry — and my experience says the real number is higher because nobody publishes their worst overruns.
What usually causes the biggest overruns? Integrations, followed by platform multiplication, followed by the accumulation of small changes nobody tracks. Discovery debt wraps around all three.
How do I stay under budget? Insist on a proper scope breakdown before signing. Budget for discovery. Define how changes get approved and priced. Get three quotes minimum and check them against market data.
Cheapest quote — red flag? Not always. But cheap quotes cheap out on something — discovery, QA, project management, post-launch support. Ask what’s excluded. If the answer is vague, trust that.
What about ongoing costs? Hosting, maintenance retainer (15–20% of dev cost annually), security, APIs, bug fixes. If the agency can’t ballpark these, ask why. They’ve done this before — they know.
I wrote this because I’ve seen too many founders sign quotes that looked right and were wrong. Get the breakdown, fund the discovery, and don’t be afraid to ask the uncomfortable questions. — Michael, CEO at Apropo