i just relisted a computer i built on ebay. the auction number is: 270130986060. the highest bid of the first auction, which had a reserve price, was $300 (w/ a 19" lcd that i just sold separately). since my component choice is highly influenced by spcr, i figure i'll post this ad to individuals who will appreciate the high quality, quiet components that i used.
to be honest, the computer is quiet, but not silent. of course, i removed all the standard case fans, so now it only has literally two fans in the entire system: the seasonic psu fan and the nexus fan on the thermalright heat sink. but because it's all aluminum, the case has a low pitched hum (due to hard drive vibration). even the top vent grills are metal, so if they get loose, they will resonate.
the hard drive is the obvious sound bottleneck. most people who read spcr are probably very refined when it comes to pc noise, so you'll understand when i say that i was disappointed at how loud a "quiet" hard drive (samsung t-series) is. if i had more time and money and wanted to make the computer even quieter, i would take out the temp. monitor and put the hard drive into the optical drive bay using some type of hard drive silencer.
this computer has been hand-crafted with high quality components, stress-tested, and is powerful and versatile. the auction will last about a week; if you have any questions don't hesitate to ask.
here's the link to the auction: