So if you take a non-US centric view and assume there's no legal repercussions and the person finding the bug has no moral compass, what exactly would prevent them from sharing the bug with a nation state and you at the same time? Sure they may get slightly less from the nation state because the bug would have a shorter shelf life, but it would still make it into the wild long before every system could be patched.

Paying more money isn't going to make someone do the right thing.