Build vs Buy Decision Framework
Should you build custom or buy SaaS? Score your use case across cost, competitive advantage, customization needs, and long-term TCO to make the right decision.
- Free Framework
- Decision Score
- TCO Comparison
Build vs Buy Decision Framework
Frequently asked questions
When should I build instead of buy?
Build when the feature is a competitive differentiator, requires heavy customization that SaaS cannot support, and you have engineering capacity. The build option also wins when SaaS costs scale linearly with users but build costs remain relatively fixed.
What are the hidden costs of building?
Ongoing maintenance (typically 20% of build cost annually), opportunity cost of engineering time, security patching, infrastructure costs, and the risk of key-person dependency. Always multiply the initial build estimate by 2-3x.
What are the risks of buying SaaS?
Vendor lock-in, price increases, feature gaps requiring workarounds, data portability concerns, security and compliance dependencies, and the risk of the vendor being acquired or shutting down.
Can I start with buy and switch to build later?
Yes — this is often the best approach. Use SaaS to validate the use case, then build a custom replacement once requirements are clear. Ensure your SaaS contract includes data export capabilities.
Build or Buy? We Help You Decide.
Our fractional CTOs have made hundreds of build vs buy decisions. Book a discovery call for objective, data-driven guidance.
Or email sales@perimattic.com