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ai build vs buy calculator

Most AI build-versus-buy debates compare a licence fee with a build quote. The real comparison includes the labour each option leaves behind, the running cost, and maintenance. This calculator puts all three paths on one cumulative chart and tells you when, if ever, building pays back.

free, no sign-up, runs in your browseropen source on GitHub
the work
buy
build

cheapest over 36 months: build an agent workflow

$972,000keep it manual
$788,000buy a SaaS tool
$629,700build an agent workflow
month 10build pays back vs manual
$0k$243k$486k$729k$972kmonth 1month 18month 36
keep it manualbuy a SaaS toolbuild an agent workflow

Build beats buy from month 16. Plain cumulative cash, no discounting. Labour left over by each option is included.

questions

why is the manual option included?

Because it's the baseline both other options must beat. A tool that removes a quarter of the work still leaves three quarters of the labour bill.

what should maintenance be?

15–25% of the build cost a year is typical for prompt and model updates, evaluation runs, and integration fixes when connected systems change.

does it discount future costs?

No. It shows plain cumulative cash so the numbers are easy to check. For a three-year horizon the ranking rarely changes.

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