> Even revealing enough details, but not everything, about the flaw to convince a potential buyer would be detrimental to the seller, as the level of details required to convince would likely massively simplify the work of the buyer should they decide to try and find the flaw themselves instead of buying.

Is conning a seller really worth it for a potential buyer? Details will help an expert find the flaw, but it still takes lots of work, and there is the risk of not finding it (and the seller will be careful next time).

> And I imagine much of those potential buyers would be state actors or organized criminal groups, both of which do have researchers in house.

They also have the money to just buy an exploit.

> The real money to be made as a criminal alternative, I think, would be to exploit the flaw yourself on real life targets. For example to drop ransomware payloads; these days ransomware groups even offer franchises - they'll take, say, 15% of the ransom cut and provide assistance with laundering/exploiting the target/etc; and claim your infection in the name of their group.

I'd imagine the skills needed to get paid from ransomware victims without getting caught to be very different from the skills needed to find a vulnerability.