> Tests are for teams of contractors that don't know how the product works.
The opposite. Tests are for people who know exactly how the product works. It's very hard to write good tests if you don't understand the product (or at least your piece).
I really hope you are being sarcastic. Tests when done properly speed up development and make your product more robust and resistant to breaking changes.
For a proof of concept that will never see production, sure, by all means don't write tests. But in my 15+ years in CTO and Principal role at smaller companies, the most expensive projects with the most downtime are always the ones without tests.
Tests make software cheaper not more expensive. And the ROI isn't even that long... all it takes is for two to three iteration / release cycles.
The talented person that built the thing knows exactly what a change will require, and how to test it before pushing his code.
Don't be an enterprise too soon.