For those who don't mind waiting 1-2 weeks for the new Gears game, Ozgameshop has what I think is the cheapest delivered price of $46.99. Game is NTSC-J but compatible with PAL, which historically has never been a problem unless you wanted to trade it in. I would think any other online buy would be the same format…
Attached is from their website
This is a pre-order - the item will be despatched to you on or before the release date of 22/03/2013 - subject to change by the publisher.
Please note: this is the NTSC-J version of the game which is compatible with PAL systems.
I love ozgameshop and all but usually with games nowadays they drop down to around $50 by the time you've received it…