lil' less than 400 gigs.
Mind you, I started collecting about twenty years ago, at the dawn of CDs. Had like three hundred CDs at the time. The change from "buy" to "not buy" was purely based on available space at the time. Each album is a memory, each genre is an era in my life; used to like most kinds of music, but never really liked hanging out with people who listen to only one type of music.
After burning my 300th cd of MP3, three friends and I decided to merge our collections, tidy up the filenames, tidy up the ID3s, and download the covers for each album. About 4500 albums got the treatment. Most batch jobs had to be divided in order to carry out most operations, and even nowadays, I can't plug the hard drive to anything running WMP or any crappy "I have to generate a library of your files before I can read them" music prog.
Over the years, some data got deteriorated, some oooold 112k albums were replaced by VBR versions, but overall I'm pretty happy with my collection.
Figure in two-three years, when portable devices get access to humongous amounts of space, I'll finally be ready to carry it all in my pocket