Most teams frame this decision as build versus buy. A more useful framing is: how far does our workflow diverge from the assumptions the product was designed around, and what does closing that gap cost every month?
Start with the divergence, not the feature list
Off-the-shelf tools encode a workflow. When your process matches that workflow, you get a mature product for a predictable fee — that is almost always the right answer.
Problems appear where the product assumes one sequence and your business runs another. Teams then bridge the gap with exports, side spreadsheets, duplicate entry and informal rules that live in people's heads.
Price the workaround honestly
Count the hours spent reconciling data between systems, the errors caused by duplicate entry, and the reporting that has to be rebuilt by hand each month. That is the real cost of the licence, not the subscription line.
If the workaround is small and stable, keep the tool. If it grows every time the business grows, it is a structural cost and custom software becomes the cheaper option over a realistic horizon.
The hybrid answer is usually correct
Very few businesses need everything custom. Buy the commodity layers — email, accounting, storage, identity — and build only the part that represents how you actually operate.
That keeps the surface you have to maintain small, while the system still fits the business instead of the business bending around the system.
Takeaway
Buy where your process is ordinary. Build where it is the business. Decide with the cost of the workaround in front of you.