Question 1

Should I build or buy my SaaS?

Accepted Answer

It depends on total cost of ownership over the software's lifespan, how differentiating the capability is, how fast you need it, and your team's build velocity. Commodity needs usually favor buying vendor SaaS; differentiating, long-lived capabilities can favor building. This calculator compares the TCO of both paths over your expected app lifespan (1–5 years) so you can decide with numbers rather than instinct.

Question 2

Should I vibe code my SaaS instead of buying it?

Accepted Answer

AI-assisted ('vibe') coding can dramatically cut build time and cost, which shifts the build-vs-buy math toward building — especially for differentiated features. The calculator lets you model AI model-stack costs and faster build velocity, then shows whether building still beats a vendor SaaS subscription over your chosen horizon.

Question 3

How do I calculate the total cost of ownership for build vs. buy?

Accepted Answer

Add up the full multi-year cost of each path. For buying: license, implementation, support, and annual price increases. For building: engineering and AI/model costs, time-to-live, ongoing maintenance, and support. This tool computes both over your chosen horizon (1–5 years, based on expected app lifespan) and recommends the cheaper, lower-risk option for your inputs.

Question 4

When does building software cost less than buying SaaS?

Accepted Answer

Building tends to win when the app is highly differentiating, has a long lifespan, vendor SaaS pricing is high or rising fast, and your build velocity is strong (e.g. AI-assisted development). Buying tends to win for short-lived, commodity, or compliance-sensitive needs. Enter your numbers to see the crossover point.

Build vs buy comparison inputs

Vendor (Buy)

Proprietary (Build)

3-year cumulative cost