Ant you are missing out you don't need a new processor most likely all you need is to invest in a reasonable GPU. Spend maybe $170 on it.
Everyone thought that you needed a Core 2 system to play Crysis but I can run it in a very high/high hybrid with an Athlon64 X2 2.2 GHz and a Geforce 9800GT (which is basically an 8800 GT) except with the flashlights (as they are too much for the CPU to handle) in 1024x768.
For the record, Crytek's answer to all the angry people getting bad performance was a Core 2 Duo E6750 2.66GHz with a 9800 GT in 1024x768 in high detail.
As you can see all you need is a sub $200 GPU. No need to upgrade anything else. Keep in mind that there is a scam going on where the low end GPUs are REALLY SHITTY. I spent $70 on this 9800 GT and the current generation sub $100 GPUs, which should be better, are MUCH WORSE! MUCH MUCH WORSE *AND* they have those fancy modern GPU numbers!