This is the cheapest I have seen this game so far (Except for PS3 Playstation Plus users, it's free at the moment), ordered a copy last night. Game Activates on Steam.
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Good price for a pretty new game, but it got a pretty mixed reception. My guess is the price will be coming down pretty quickly and we'll likely see better deals over the Christmas period, though if you want it now it's good deal! Also nice that it comes as a boxed copy.