OK, here's my $.02
I ordered a 350W highpower PS from this site a month or two back. They wound up sending me a 400W power supply "by mistake". So I did a little pricewatch research, looked at the label and found a strikingly similar label on a 400W PS on another Yahoo store for $22. Cheap cases can be had for $15-25, making $46 a warm price at best.
Sorry, I don't remember if it was AMD approved (hard to tell, there wasn't a manufacturer on the label)