At the moment one may only make an offer to sell something at the auctions. How would you like to be able to offer to buy something? :)
I think introducing an opportunity to wish to buy something at a given price will make the current glitch market a very interesting place to hang out. (especially if you can't actually launch the client and.. eh.. play covertly for one reason or another... )
PS: I saw that it has been already proposed. Sorry.. :S