Not every problem needs custom software, and a studio that never says so is selling, not advising.

Buy when the problem is common and solved. Accounting, email, payroll and payments are all things thousands of companies need in the same way, and an off-the-shelf tool will beat anything custom on price and reliability.

Build when the process is your process. If the way you handle a workflow is part of how you compete, forcing it into someone else's template quietly makes you worse at the thing you are good at.

The interesting projects sit in between: buy the common parts, build the part that is truly yours, and integrate them well. That is usually the right answer, and it is the one we reach for most.