Used is $37.99. As posted in the weekly ad thread, just the PC version was $19.99 this week.
Camelcamelcamel hadn't updated the Amazon PS3 price, was still showing $47.45. EDIT: It just dropped on their tracker. The image below is live.
Searched the threads and didn't see it posted. Looked last night on Gamestop, pretty sure it was full price.