I've been having a lot of trouble getting good answers out of SO lately without offering large bounties. I make a very big effort to make sure I ask clearly articulated questions with well defined steps, and also to respond to comments asking for clarification immediately.
Unfortunately, it has reached a point where even bounties don't attract good answers any more. I have put a bounty of 100 rep on a question recently that has attracted two responses that don't even really qualify as answers as they make it clear the respondent has not even read the question.
I'm stuck in the position where I have to offer bounties to even get a bad answer, and for that privilege I have to keep slicing off bigger and bigger chunks of my own rep. If I don't get any upvoted answers in the bounty timeframe, I don't see why I can't have my bounty back. In that situation, once I get the 100 rep bounty back, I'll almost certainly offer 200 rep. If the 200 rep bounty doesn't get me anywhere, maybe it's worth 300 to me. Under the current system, that costs me 600 and I may not even end up with an answer after that.
Yes, I could game the system (though not much, by my estimation) by never upvoting any of the answers on my bounty questions, but the collaborative nature of SO voting should rectify that - someone else will probably see the question (especially with a big bounty on offer) and upvote a good answer anyway.
Also, it could be set up so an answer made during the bounty period but accepted outside of it with no modifications gets the bounty anyway, which would get around the case where people wait until they have their bounty back before accepting an answer.
You could then game that further by never accepting answers, but then your accept rate would plummet and I certainly wouldn't touch your questions any more...