For anything you would be doing with a GTX 670, an i5-3570k is probably good enough and it would cost $300 less. Even if you went with a 3770k it would still be $200 less.
I heard Micro Center is going to be selling 2500ks for $100, which is also a really good deal on a gamer's processor. Maybe the best bang for the buck out there.
That being said, you should definitely be able to save about 25% off the entire cost of the new PC.
The problem is more trying to actually get the deals, the good stuff sells out pretty fast. Luckily, online shopping on Black Friday is really good too. You can get a lot of cases and stuff at 50% off.