dood, I got this system and built onto it and I'm in for $600 (a year ago). It's got 2 video cards (still $75-100 each), 2 19'' LCDs, office 07 ultimate, a tv card and an audigy 2 soundcard. The case is still $80+ online too, so STFU.
I've hit an all time low, talking about my home PC on a fitness board. I'd like to see if I can go lower than this.
Go with the highest your board supports. Might as well stretch the life out of it the most for your $$. Also you're wasting a gig or so of your memory if you're using 32 bit XP. That extra gets allocated to system functions and you won't see any performance increase over 3 gigs unless you're using 64 bit Windows or a non-Windows OS. Actually 2 gigs is still considered the sweet spot for 32 bit XP.
If you mostly use your PC for gaming and already have 4gig of 667 you are better off getting a new GeForce 9800 card and keep everything else. The only case in which you would really see a difference is if you are doing really heavy duty video editing and compiling, but if that were the case you'd be using a MAC.
At the speed that information is getting written to memory, the bottleneck would be your hard drive most likely. Get some WD Raptors and run a striped raid config for gaming.
I've built my own PC's since '97 and work in IT for a living. If you want to throw your specs out i can tell you what you would most likely want to change.
Your 667 memory may very well be capable of 800 anyway. It's just like when Intel sells a chip at 2.8ghz when it's perfectly capable of 3.6ghz. Smart peeps just buy the cheaper chip and OC that puppy to 3.6 then spend the savings on a grip of crack rocks and some MD 20/20.
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