I used to answer with "What's the most you're willing to pay?" but don't even bother anymore.
It just seems somewhat lazy on the buyers part to me. I always check sold eBay listings and previous BST listings and list for the same or lower. I guess if I had trouble selling an item I needed to get rid of I might be inclined to answer, but I haven't come across that situation yet.
Fair enough. Your feedback speaks for itself, obviously a top notch seller.
I guess it proves that “to each their own” is very true.