Funny thing is I bought this rig to play SH3 (thats how old it is) my former rig was a 1mhz PIII that I spent more time tweaking files, adding cards and generally farting around with than gaming. It was speced for Janes 688I, Janes WW2 and Grand Prix Legends box release. But it ran EA sports F1 99, IL2 Sturmovik and sort of IL2 FB with alot of work. SH3 did it in.
So when I bought I knew what I needed, and AMD and Intel were in a hardware war with new chips coming out every month. If I had my money together in March, I would have wound up with a 5xx Pentium with a smaller Bus size (333 or 500mhz I think) and AGP graphics. But I was forced to wait and I got the then hot 800mhz bus PCI graphics and 6XX series Pentium at a great price. Since then only going to a 24" monitor and SH4 forced a major upgrade to the 512MB 7950GTO card.
I write all of this to point out that there are sweet spots, especially if you are not into the Quake DOOm and Crysis type of games. Simulators are released only every couple of years, and getting a 12 month old former top line cpu can really be an advantage. IMHO get the most forward speced mainboard you can (socketed for the newest class of chips) check out whats comming down the pike,info on Intel and AMD next designs are on the web( check out
http://www.anandtech.com/ ) for the release pattern on chip classes and know the type of chip in the computer you are buying. Wikipedea actually has alot of info on this stuff.
Of course builders know all this and a lot more, but alot of guys buy off the shelf and may not realize that the chip/board/socket configuration they are getting is at the end of its development cycle and literally has no future.