Got mined boxed up. It's a good keyboard, but I'm kinda over the ergo thing. Now it's mainly an awesome piece of history.
IIRC four or five years ago they were pretty expensive (say $400-600), then as prices were peaking a number came out of the woodwork and some were going for up to $1600 if condition with very good and you had some perks, like the number pad or original wrist pads, etc. There were a lot of international buyers pushing up the prices. Lately prices have dropped, but you'll still see them going for $500+ for the most part. Market has definitely slowed down.