> 70K is the median programmer income in the US. (Based on a very thorough let's look at the first thing Google regurgitates!)

BLS, which while not perfect has far better data than most other sources trying to do this independently, says $84,280 in 2018.

https://www.bls.gov/ooh/computer-and-information-technology/...

> It should have been enough to fund a business analyst and an app developer for a few months

Probably. But that doesn't matter if no one advised the client that they needed a realistic, production-like field test (most of the cost for which wouldn't have been part of the contract, since it would have been client side; the developer-side support for that is a small fraction of the cost.) Errors in report definitions that exclude some data in circumstances that don't come up in developer-constructed testing scenarios is, like, not at all uncommon.