As a company that builds software, our incentive is to recommend building. We routinely tell clients to buy instead, because a project that should have been a subscription is the fastest way to lose a client's trust permanently.
Is this how you compete?
The first question separates most cases. Payroll, email, accounting, helpdesk — nobody chooses your company for these, so buy the best available and move on. The workflow that makes you distinctive, the thing customers describe when recommending you, is where building earns its cost.
Buy what makes you the same as everyone. Build what makes you different.
How much of the need does the product cover?
Above roughly 80%, buy and adapt your process to the tool. Below 60%, the workarounds usually cost more over three years than a build. The dangerous middle is where teams buy, then spend continuously on integrations and manual reconciliation to bridge the gap.
Count the total cost, both ways
Building costs more than the build: maintenance, hosting, security updates and the attention of people who could be doing something else. Buying costs more than the licence: integration, data extraction, per-seat growth and the switching cost when the vendor changes direction. Compare over three years or the comparison is not real.
Whose roadmap decides yours?
When you buy, your capabilities are bounded by a vendor's priorities. Usually fine. Occasionally fatal — when the thing you need next is something they have declined to build, or when their pricing changes at your scale. Ask what happens if this vendor never ships another feature you want.
The hybrid is often correct
Buy the commodity components and build the layer that connects them into your specific workflow. Payments, auth, email and search are solved; the orchestration between them frequently is not. This is the answer more often than either pure option.
Decide in writing
Record the decision and the reasoning, including what would change your mind — 'revisit if seat cost exceeds ₹X' or 'revisit when we need multi-currency'. This turns a permanent argument into a scheduled review and stops the question resurfacing every time someone new joins.
