It wouldn't ruin anything of the sort, at least not in my opinion. It would get buyers and sellers together much more often. Ideally, there would even be a way to post a message about the item or to the seller. There are few enough people on right now, and not everyone is on at the same times. I would like to be able to sell my crafted items, or buy others, even if we are not in-game at the same times. I don't necessarily want to have to hop on at a peak time, when i need to be doing something else, just to arrange for an item to be purchased.