I feel like I got away pretty good, spending under $800 on my Athlon 64 3200+, 1.5GB DDR400 RAM (512+1024), 128MB GeForce 5700LE video card, 120GB WD 7200RPM HDD, 16x DVD-RW drive, 17" CRT, and a nice solid aluminum Antec case with a 400W PS. The only thing I'm really unhappy with is the cheap Chaintech motherboard. I'll probably be replacing that soon, because this one is just unforgivably shitty.
While we're on the subject, anybody have any experience with Asus motherboards? Before this one, the most recent ones that I've used are a couple of MachSpeeds, a couple of Gigabytes, and a Soyo. The only one I was unhappy with is the Soyo.
As far as video card noise goes, the quietest card with the best performance I ever had was a 128MB Radeon 9250, and that was quiet because it didn't even have a fan. The only game that I ever really played on it was Half-Life 2, and it handled those graphics at 1600x1200 resolution pretty easily, but I have no idea how it would measure up to the FX5900XT. You might want to check into changing your case, because that was the most significant noise reducer for me. With this setup, I can hardly tell my computer is on.
Case is heavy as hell, though.