Subscribing to software is the right call for most businesses, most of the time — cheap to try, cheap to leave, someone else handles the maintenance. But "usually right" isn't "always right," and a fair number of growing companies keep paying for the wrong side of that trade-off long after it stops making sense.
Start with the honest default: buy
If you're not sure which side you're on, buy. Off-the-shelf SaaS wins by default because of three things custom software can't easily match early on: it's available today, it's cheap relative to a build, and someone else is responsible for keeping it running and secure.
The five questions that actually flip the answer
1. Is this workflow what makes you different, or just what makes you functional?
Every business needs a CRM. Very few businesses have a genuinely unusual sales process that a CRM's settings page can't accommodate. If your workflow really is unusual — and that unusualness is part of your competitive advantage — a generic tool will always feel like it's fighting you.
2. Are you paying for four tools to do the job of one?
A common pattern: a CRM, a separate quoting tool, a separate invoicing tool, and a spreadsheet gluing them together, each with its own subscription and its own login. Add up what that actually costs — in subscription fees and in the manual work of keeping data in sync — before assuming it's cheaper than one custom system.
3. Have you hit the ceiling of what "settings" can do?
Every SaaS product has a point where the answer to "can it do X" becomes "not without a workaround." If your team has built an elaborate stack of workarounds just to make a tool behave the way your business actually operates, that's the tool telling you it's reached its limit.
4. Does this process touch a large, ongoing cost?
Custom software has a real upfront cost. It earns that cost back fastest when it improves something you do constantly and at volume — inventory reconciliation, claims processing, scheduling — not something you do occasionally.
5. Do you actually own your data today?
If leaving your current SaaS vendor would mean losing years of clean, structured data, that's worth weighing on its own — independent of features, that's a real business risk sitting inside a subscription.
None of these questions have to point the same direction. A business can reasonably buy its accounting software and build a custom CRM around a genuinely unusual sales process — the decision is per-system, not all-or-nothing.
What a realistic middle ground looks like
The build-vs-buy choice isn't as binary as it sounds. A common, sensible path: keep off-the-shelf tools for the genuinely generic parts of the business (accounting, email, scheduling), and build custom software specifically for the one or two workflows that are actually core to how you compete — with integrations connecting the two rather than trying to force everything into one system.