When you propose a bounty, these points are immediately subtracted from your score, and can never return, even if there is no satisfactory answer.
I think this is unfair; can someone explain the reasons for such a policy?
For example, I have several questions, such that the answers would be very precious for me, and I am ready to give many of my points for them. But I am not willing to risk loosing many points in the case nobody gives an answer which would satisfy me.
EDIT. If bounties are "advertisement fees" then what is the point of having them in the range 50-500? All bounties get in a quite short list which is called "featured". Then there in no point at all in paying more than minimum amount. Or the amount should be proportional to the time it stays on this list:-)