Not every box has to host your entire pr0n and mp3 collection, ebaycj. Nobody is buying these to act as file servers.
Even a 3 GB drive is enough for a basic Linux installation. I've got a Slackware box on my back porch for with KDE, Firefox, Nvu, Mozilla, OpenOffice, Abiword, Gnumeric, etc., plus a 500 MB swap partition, and I've still got 600 MB free. Works fine for listening to music (the files are on another machine), browsing the net, email, etc. And if someone decides they want it more than I do, I don't feel too bad, since its just a Celeron 400 with 128 MB that I got for free.