One commenter already clarified how bounty amount is related to black market value. Now a lot of others might seem how Google doesn’t value security enough. (Or other companies).

But one has to understand that for security purposes they SHOULD pay as little as possible. If they pay out more there is more incentive in finding bugs and then there unfortunately you’ll also raise more black market.

So GTO strat is to just cut off black market with as little money as possible.