http://www.wowinterface.com/downloads/info7266-WTS.html
Good, but very old addon. It will automatically link products to the trade channel attributing to him the price.
For example, if you link products in private and ask "how much", the addon automatically answers "45g"
You can insert any thing in the addon window and indicate the price for a product or a bundle. Put the time after which will link the trade channel, and go smoke.
but need fix for 4.0.3, who cant?