Yes & no. Traders tend to bid too conservatively. They want to buy stuff too cheaply. When a trader is the highest bidder for an item, generally he's getting "good value". The other side of the coin is that they can give up too soon on an item that has bigger upside potential than they can imagine.
Traditional auctions are a luxury, for the those who go there to savour the ambience, to enjoy the fame, for those who can throw their money away.
These are fascinating responses from traders that I respect...could some low lifes now respond...hehe just kidding....
I think auction houses are more for floor traders. Upstairs traders can't do it. It's a bit like poker.... Online player vs Table players.
All depends on just how badly you want something. If you wait until an item reaches an auction house, then I am very much afraid you are too late.