Build versus buy is where a lot of money gets spent badly. Vendors want you to buy their platform and bend your process around it. Developers want to build. Both have an incentive that isn't the same as yours.
The honest answer depends on one thing: how well an existing product fits the actual job.
Buy when a product genuinely fits
If a mature product already does what you need, buying and configuring it beats building something to compete with it. A $25,000 product that fits your work is a better deal than a $100,000 custom build that does the same thing: you get proven software, someone else maintains it, and you're live far sooner.
- Your need is common and well served by existing tools
- The product handles your critical step, not just the easy ones
- You can adopt it without reshaping how you operate
- You'd rather someone else own the upkeep and updates
Build when nothing fits without heavy compromise
When your workflow is specific to how you operate and every product forces painful workarounds, a small, focused custom tool is often cheaper to own than the manual work it removes, and cheaper than a big platform you'd only use a fraction of.
- No product fits your one critical step without heavy workarounds
- The task is high-frequency and worth a purpose-built tool
- You need two systems connected that nothing off the shelf joins
- A small first version solves the problem and can grow later
The test that cuts through it
Add up the real cost of buying (license, configuration, and the workarounds you'd live with) against the real cost of building and maintaining a tool that fits. Compare them honestly, including the option of changing the process so you need neither. The right answer is whichever solves the problem for the least total cost, not whichever is more impressive to build.