Try searching for a kringle collection, for example. There are alot of trades like this one, http://www.tf2outpost.com/trade/4950335, which, although are active enough to avoid the auto-closing, are still massively out of date, and contiune to sit there due to people asking "wtf with the price man" in posts at the bottom.

Obviously nobody is going to buy/sell items for a outdated price now, and if the trader hasn't bothered to update or close it, i see no reason that people should have to sift through these now-pointless trades to find one that reflects current prices.