I've contacted independent brokers before, many of whom allegedly resell primarily to "the US government". When asked about hypothetical Tor 0day, they quoted a price of $150,000 before their 20% broker fee. So I'm not sure that 6 figures for most trivial vulnerabilities fits the market.
(And obviously, I don't have such a 0day to sell, so I can't prove that they would actually pay up.)
(And obviously, I don't have such a 0day to sell, so I can't prove that they would actually pay up.)