@John, not worth the bother for you - and other 10k+ folks. But there are a lot more people with much lower reputation. Someone with 25 rep may be attracted enough to a bounty of 25 (100% of their current) to try to answer that question. Additionally someone with 100 rep is probably very unlikely to offer a bounty of 50 for a question they really want an answer to. Let the little people play I say.

I think this is a great idea as well. Additionally I'm surprised I haven't seen any suggestions for lowering the minimum bounty one can put up. the way I see it, Lower bounty minimum = more bounties offered = more answers posted