I read this on cheapassgamer and dang if it ain't a killer deal.
Batman Arkham City goes on sale for $30 this next week (March 4 - 10) at Best Buy. That's a good deal. It's an even better deal if you buy the latest issue of @Gamer magazine (sold at Best Buy) and use the coupon for $20 of Arkham City. That's 10 bucks if you already have the mag, or $15 if you don't.
Personally, I just bought a year subscription today for $15 and ended up buying Mass Effect 2 for $5 because it's normally 20 and there was a $15 off coupon for that. I already own the PC version, but I thought playing it again on 360 would be cool for only $5. On Sunday I'll head back and get Arkham City for $10. Just had to let my GB brethren in on the deal.
EDIT: credit where credit is due.