First question why 17.3"?
Really those laptops are huge and no longer necessary to buy that size to get good gaming.
Look for 3rd Gen Ivy Bridge (just out), and at least Nvidia 650M, or AMD 7750 or betters. Avoid old gen tech at all costs. In note books the 22nm or 28nm chips on new tech makes a huge difference.
A good choicehttp://www.logicbuy.com/deals/coupon-new-hp-pavilion-dv7t-17-3inch-notebook/11471.aspx
The HP Envy 15 is powerful, and the highest quality build, light and powerful gamer.http://www.logicbuy.com/deals/hp-envy-15-core-i7-laptop/14729.aspx
After searching.... most of what I find is out of your price range.