Sorry if this isn't the right section, but it seemed appropriate.
Basically I have gotten the Opportunity to buy a computer with the following specs
i5 2500k O.C. to 4.5 gHz, with liquid cooling as well as four fans
GeForce GTX 570 1.2GB Video Card
16GBs of (4X4GB) DDR3-1600 RAM
Western Digital VelociRaptor (WD3000HLHX) 300 GB 3.5" SATA Hard Drive
700W Power Supply
Windows 7 professional
All brand new, for $500
Good deal? And what kind of performance would I get on modern games.
That deal almost is too good to be true. Unless you know the person and can verify it isn't stolen or doesn't have some weird underlying issues, I would pass. If you know the person and it's all legit, this is a super duper deal. It would handle all modern games very well. As mentioned above, this system new would probably be sold for $1000.
I play by the rule "if it's too good to be true it probably is".