Thinking about picking up Portal 2 on the Xbox 360 or PlayStation 3? Two player co-op campaign catch your fancy? Then I have good news for you and your wallet! Amazon has the game for $54.99 with release date shipping...but wait...there's more! If you pre-order the game now you'll earn yourself $20 in videogame credit towards another purchase on Amazon.com.
If you hapen to pick up the PS3 version of the game, you'll be treated with a truly excellent value - The PS3 version of Portal 2, the PC version of Portal 2 (Steam required) and cross platform co-op play between the two if you so desire. Not a bad deal for a net $34.99 - plus you support Co-Optimus with your purchase.
Source: Amazon.com