ebay dot com
I can't say I recommend ebay given the high chance of something being damaged during transit or being labeled as working when it hasn't been tested in 20 years, but it's really the only place online I see this sort of stuff pop up. Best thing you can do is set up a bunch of saved searches and jump on ones at a reasonable price. "Reasonable" here means "quite possibly broken and unrefundable." Do not take sellers for their word on a device being "tested" unless they can prove they've actually operated the device with a video floppy disk inserted.
