Searched myshopping seems this is the cheapest.
Also XB0X Games on special:
Forza Motorsport 4 - Xbox 360 $22
Halo Anniversary - Xbox 360 $25
Battlefield 3 - Xbox 360 $24
Gears of War 3 - Xbox 360 $24
Rage Standard Edition - Xbox 360 & PS3 are both $12
Nintendo DSi or DSi XL are both $128
Nintendo Wii Console Bundle White with Mario Kart $148
I also saw my local HN have COD3 for $28
Edit: Added expiry date from T&Cs, but only available until stock runs out.
Thanks. Just grabbed Gears 3.