I have noticed myself that some items go for more than they are really worth but if you set out from the start with a figure in your mind then there are some amazing bargains to be had! I am playing with a set of Macgregor Tourney MTs that were in immaculate condition (still are) off ebay for £65($125) which included shipping
and I am playing just as well with them as my I3s which as you can imagine cost a lot more!
I guess some people just get caught up in a bidding frenzy or something and don't want to miss out on an item as it were?