Most modern games are GPU-bottlenecked, rather than CPU. In fact, most of those modern games (with a few exceptions, like ArmA II) will run perfectly fine on a $60 Athlon II X2 240, given that you have a good enough graphics card. A Core-i5 is already somewhat overkill if you're talking about just using it for gaming, so the i7 would be a complete waste.
So, the question that I'd ask you is: What are you using your computer for? If just gaming, then you should be good to go for 3-4 years or so with the i5 (at which point a CPU with the processing power of the i7 will be dirt-cheap). If you're doing heavy a/v editing, game development, or something similarly CPU-intensive, however, then the i7 might be a worthy investment.
Regardless, that is an excellent price on an i7. Damn, I wish I had a Microcenter near me.
Also, a $500 video card is - and I cannot emphasize this enough - a complete waste. Buy a $150 one now and another $150 one three years from now. You'll save yourself a good deal of dough without sacrificing performance.
"'Casual games' are something the 'Game Industry' invented to explain away the Wii success instead of actually listening or looking at what Nintendo did. There is no 'casual strategy' from Nintendo. 'Accessible strategy', yes, but ‘casual gamers’ is just the 'Game Industry''s polite way of saying what they feel: 'retarded gamers'."
-Sean Malstrom
Essay Pro