Players would only use it for items that they couldn't sell on the AH at a profit over vendoring. And in that case, they'd more likely vendor it to have gold in their pocket.
Idea would not work.
"I quit WoW."
If I say it's Azshara next enough times, eventually I'll be right. So here we go again. It's got to be Azshara next, so get ready for the Sylvanas expansion we inevitably get instead!