CPU help!!!!!!any knowledge about cpu building

alright here the scoop...i have a laptop(acer aspire 3630) and felt it was time for a desktop....so i went to the store and the guy says he can do a cpu with:
AMD sempron (64bit)
2 GHz Ram
160HDD
DVD burner
cpu case
---------------
$650
so i was thinkin is there anything i shud add to make it better(rungame like "call of duty 4" and rainbow 6 vegas....
any suggestions on a sick video card to install and price
any cpu comprehension will do!!!!!!!!!!!!

alright heres the scoop...i have a laptop(acer aspire 3630) and felt it was time for a desktop....so i went to the store and the guy says he can do a computer with:
AMD sempron (64bit)
2 Gigs Ram
160HDD
DVD burner
Computer case
---------------
$650
so i was thinking is there anything i should add to make it better(run games like "call of duty 4" and rainbow 6 vegas....)
any suggestions on a sick video card to install and price
any computer comprehension will do!!!!!!!!!!!!

Fixed
Yeah that should be able to run R6V, but if you want to run CoD4 get a decent video card, nvidea is the way to go if you have the cash.

[ace]

For $650? That's garbage bruh. We don't know whether it will run anything though until you tell us the video specifications. What is the specs on the processor? And like 1/-0 said, get a geforce video card. If you want to run CoD4, then my 8400GS runs it fine at medium-high settings without any skip. But if you want to get something real nice then buy a 8800GT That's about as far as my knowledge in video goes other then most of the time you pay for what you get. Also what kind of motherboard will be in it?

I built this one for $380 w/ parts from newegg:
Motherboard: Biostar TA770 A2+
Proc: AMD Athlon 64 X2 2.3Ghz (OC'd to 2.5)
Ram: 2GB of OCZ Platinum
Video: ECS Geforce 8400GS
HD: 250GB Barracuda SATA
Case: Logisys Area 51 Silver
With another 200GB WD IDE HD, and a 16x DVD burner IDE
And finally Vista Ultimate (yep)

So yea. Even with labor costs, $650 is pretty high for what your getting.

man u guys are awesome...like i jus wnt to put together sick computer for speed...and gaming...1-/0 ur cpu sounds great at a good price....like i might copy what u got and tell the maker of my cpu to make that one....buh might pay 400$(cuz i live in australia..perth)....so yea
and andder quickie....i have broadband yea.and lik im getting like 8kbps max on torrents wid 30 seeds..like is that not regular or not. i pay for 10GB download limitt soo..whats wrong(im using a laptop and if i get this desktop will it run faster//and thanks for the comments