How good is this rig?

[Envy]

Hi, there is this build on craigslist for $300 that comes with Win 7. I was wondering what you guys think it's performance would be on todays games (BC2, Metro 2033, Crysis, etc.)
This is the ad:
"AMD Opteron (x64) dual core (aftermarket fan on it. Can easily be overclocked to over 2.8ghz)
LanParty Motherboard (supports SLI)
2 gigs of OCZ ram
500G HDD (sata)
ATI HD4850 512 video card (sorry Mike).
DVD burner (cant remember the make. I think its LG)
built in Gigabit lan and 5.1 audio.
Antec Case
550W power supply. "
Do you think I could add more RAM, another CPU, and xfire another GPU later on?
This is the exact mobo:
lanparty ut nf4 SLI-DR

 

[killem2]

Its not the greatest, it certainly can play those new games but it isn't going to be mind blowing.

As far as upgrading possibilities, it depends on that socket. I'm not sure what the x64 opty is there were lots of them. I'm guessing am2