Are computer components expensive in America? I thought they were cheaper than here, you have that Newegg site that everyone seems to love some much...
I ask that because the build I'm planning (by this time next year, if I can find a job when I turn 16) is ~ £640; and that's kind of... ridiculous:
2 GiB of DDR3 memory at 1333MHz, a Phenom II 965 at 3.4 GHz, a 9800 GT, a 650 W Antec PSU, a 300 GiB WD hard disk, an MSI motherboard (I've heard that their boards are good... I don't really know, though) and the most awesome, most ridiculous RaidMax case I could find:
http://www.digicom24.de/images/2009-01-09_18.29.19_Raidmax%20Tornado%20GS.jpg
And to top it off, this beast is my heatsink:
http://www.quietpc.com/files/images/products/asus-silentknightal-large.jpg
One company I tend to seek is Asus; I've heard from many reliable sources that their hardware has superior quality to most companies... I hope that's true, because it's damned expensive. I wanted an Asus motherboard, but it was like £200; so I went for the MSI... the graphics card is an Asus though.
I guess if you hunt for long enough, you'll find good deals... Also, in this country at least, hardware prices went WAY down after Windows 7 was released. One of the few things I can thank Microsoft for. If you can afford to buy a new system, now is certainly the latest you should start to look for parts. But hell, for all I know you've got lots of experience with this and I probably sound like a 7 year old on Christmas...