Best Buy is offering Prince of Persia: The Forgotten Sands for the Xbox 360 for only $9.99. It is out of stock right now but you can still order and they will ship when available.
I price checked this all over and here is what I found it for on other sites:
- Future Shop: $19.99
- Amazon.ca: $19.52
- The Source: $54.96
- Gamestop.ca: $19.99
Just looking at the competitors above, you know you are getting a good deal from Best Buy. Free shipping on orders of $20 or more, so maybe see what else they have lying around.