By submitting a bug through a bug bounty system you place the reward into Facebook's hands. Following the same argument you can say they can offer $1, because t

By submitting a bug through a bug bounty system you place the reward into Facebook's hands. Following the same argument you can say they can offer $1, because they are the only organization interested in the bug. After all exploiting a vulnerability puts you on the wrong side of the law. However I do believe saying you discovered a pretty serious bug by putting it on a market sends a strong message. Your system is vulnerable and you are too cheap to pay up.