Batman: Arkham Asylum from Amazon for only $47.99. There's no need to pull out your handy Bat-Price-Reducer either. You need only place a pre-order for the Xbox 360 or PS3 version. Then, at checkout, simply enter the code 5OFFARKM for five smackers off Amazon's asking price of $52.99. Using free shipping, that's a brand new copy for $48. Even better, using the same coupon, the PC version can be had for only $40.
That's a deal only the Joker could refuse. After all, saving money is no laughing matter.