Compare · 7 min read

Custom app vs. off-the-shelf software: which is right for your small business?

Off-the-shelf SaaS feels like the safe, modern choice — until you've paid $24,000 over four years for software that still doesn't quite fit. Here's the honest framework for deciding.

By · · When to build vs. when to buy

The 4-year cost no one talks about

A typical SaaS tool for a small business is $40–$200/month per user. For a 5-person business on a $99/month tool, that's nearly $24,000 over four years — and you own none of it. Stop paying, lose everything.

A custom app at $5,000–$15,000 is a one-off cost. After year one, you're done paying.

That maths doesn't always favour custom — but it does more often than people assume, especially for tools you'll use for 3+ years.

When off-the-shelf SaaS wins

  • Generic, well-served problems — email, accounting, CRM, project management
  • You're early and unsure — paying $50/month to test a workflow is cheaper than building it
  • You need it tomorrow — SaaS is instant
  • You'll use it for under 2 years
  • You'll have 0–5 users — per-seat pricing stays manageable

When custom wins

  • Your workflow is genuinely yours — the SaaS can't quite fit, and you've contorted the business to match it
  • Per-seat pricing is becoming painful — 10+ users at $99 each is $1,000/month forever
  • You need integrations the SaaS doesn't support
  • You'll use it for 3+ years
  • The data inside it is core to your business — you should own it

The hybrid: "thin" custom around the SaaS

Often the right answer is neither/both. Keep using Stripe for payments, Xero for accounting, and Calendly for bookings — but build a thin custom app that ties them together your way. You get the best of both: you don't rebuild what's already great, but you get a workflow that actually fits.

The cheapest custom app is the one that does the 20% your business genuinely needs and leans on existing tools for the other 80%.

A 5-question framework

  1. How long will you use it? Under 2 years → SaaS. Over 3 years → consider custom.
  2. How unique is the workflow? Generic → SaaS. Genuinely yours → custom.
  3. How many users? Per-seat × users × months → compare to a one-off custom cost.
  4. How important is ownership? Core to the business → custom.
  5. Can you describe the app in one sentence? If yes, custom is more achievable than you think.

What people get wrong

  • Underestimating SaaS lock-in. By year 3 you've trained staff, built workflows, and your data lives there. Switching is rarely "free."
  • Overestimating custom risk. A well-scoped 8-week build with a good developer is lower-risk than people imagine.
  • Forgetting maintenance. Custom apps need ~5–15% of build cost per year for upkeep. SaaS "maintenance" is the subscription.

Thinking about your own app?

Send Charlotte a one-sentence postcard about what you're building. She reads every one personally — usually replies within a day.

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FAQs

Is custom always more expensive upfront?
Yes — almost always. The trade-off is that the cost stops after year one, while SaaS keeps charging forever. Run the maths over the realistic lifespan.
Can a custom app integrate with the SaaS I already use?
Yes — Stripe, Xero, Google Workspace, Slack, Calendly, MYOB and almost every modern SaaS exposes an API. A good developer will integrate them into your custom app rather than replace them.
What about ongoing maintenance for a custom app?
Typically 5–15% of the original build cost per year. Most months it's nothing; occasionally something needs updating. Usually offered as an optional, not-locked-in retainer.
Will I be locked in to my developer for a custom app?
You shouldn't be. At Warp we hand over the source code, repos and accounts at launch — any developer can pick it up from there. That's the whole point of "custom."