Go Hastings, if you’ve never used them, is an excellent resource for getting good deals on entertainment stuff. They carry video games, dvd’s, blurays, cd’s–you name it. Sometimes their deals are exceptionally good, like today.
Gears of War 3, yes a used copy (their used games are always like mint in my experience, but just FYI Gears doesn’t come with any DLC codes or online passes anyway), is selling for less than $15 shipped today. You’ll have to use coupon code to ensure the price drops to where it should be, but then you’re golden. Go get your Gears on!