With the release of Resistance 2, I'm guessing they're trying to make a few extra dollars on it.

Circuit City retail stores and Amazon both have Resistance discounted for $19.99, with the release of Resistance 2 coming just a few days away along with the voting that will decide Americas Future.

Other retailers such as best buy and Gamestop will probably follow suit. If not then just stop by your local Circuit City store and pick up yourself a copy if you have not played the game or if you traded it in and wish to play it again.

Source