> And how much?

Mercor, one of the larger vendors for contracting with experts to create bespoke data, says on their webpage they're paying $3M/day to their contractors for data.

So well into the billions of dollars a year for bespoke training data.

That's also ignoring the RLVR data labs can get from software - they can use the vibe coding sessions as training data as well without paying more.

They are just one of many.