The bounty procedure is a bit messy if you ask me.
Actually you agreed to it on the very first page if you were able to read it because it's so small:
However, it is not deducted immediately: it's only deducted two steps later, so you have two cancel buttons in between.
This sentence should be moved on page 3 of the "bounty wizard", to the place where the Next button really applies the rep change. The button there should not be called Next but "Deduct rep and start bounty now" or similar (at least "Finish").
What did I get in return for my deducted points?
Attention. People certainly looked at it - yet, unfortunately, there seems to be no answer at this time.
Consider thinking of a bounty like walking 100 minutes through a city, asking all kind of people for help. You go home without an answer. Nobody will refund the 100 minutes you spent.
That said, bounties work well on Stack Overflow, because you can work on a solution: do research, do some coding, post the result. I don't think they work well on this site, because there's no way of working on a bounty: you can do research, but that's it. Either you know an answer or not. Therefore I'd consider keeping the rep and using the resulting privileges to do useful stuff like moderation (or winning T-shirts, hey, when will they be shipped?).