Every founder asks this question, and every vendor’s first answer is some version of “it depends.” That answer is honest, but it’s of no help to the client. Here’s what it actually depends on, so you can estimate your own range before you talk to anyone.
Scope is the biggest lever, by far
A tool that replaces one spreadsheet costs a fraction of a platform that replaces six systems and adds a client-facing portal on top. Most cost surprises don’t come from bad estimates. They come from scope that grew quietly after the estimate was set. The fix isn’t a bigger contingency budget. It’s a Discovery phase that pins down exactly what’s in and what’s out before pricing happens, so the number you get is a number you can trust.
Integrations cost more than new features
Building a new screen from scratch is often simpler than connecting to a system you don’t control. Every integration, whether it’s QuickBooks, a payment processor, or a legacy database nobody documented, brings its own quirks, rate limits, and edge cases. A project with five integrations will almost always cost more than a project with five extra screens, even though the screens look like more work on paper.
Custom does not mean starting from zero
A lot of what looks custom is actually assembly: proven authentication, hosting, and payment infrastructure, combined and configured around your specific process. The truly custom part, the part that costs real time, is the business logic unique to how you work. Knowing which parts of your project are genuinely novel and which parts are standard plumbing is most of what separates an accurate estimate from a guess.
Ongoing cost is a separate number from build cost
The build is a project. What happens after launch, meaning hosting, monitoring, bug fixes, and small improvements, is closer to a subscription. Vendors who only quote the build number and leave the rest vague are setting up a conversation you don’t want to have six months in. Ask for both numbers upfront, even if the second one is an estimate.
The real comparison is not build versus buy
Comparing a custom build’s price tag to a $30-a-month subscription looks bad for custom software every time, but it’s the wrong comparison. The right one is: what does the subscription cost you in workarounds, per-seat fees as you grow, and the two other tools you’re paying for because the first one doesn’t do everything you need. Custom software has a higher number on day one and, for the businesses it actually fits, a lower number by year two.
What actually gets you an accurate number
A real estimate comes from a Discovery phase, not a sales call. That means someone maps your actual process, counts the integrations, and separates the standard plumbing from the genuinely custom logic before anyone commits to a figure. Anything faster than that is a guess dressed up as a quote, and guesses are exactly where the surprises later come from.
If you want a number you can actually plan around, a free 30-minute conversation is enough to tell you whether your project is a small build, a large one, or somewhere in between: info@femmesoft.us or +1 484 978 0339.