This is a rather rare occurrence, and in the time I've been tracking them I have seen Foleos on Ebay twice a year, at most.
What's the Foleo, you ask? In terms of hardware, it was a netbook. But in terms of market presence, it was Palm's last big fiasco (before the TouchPad).
Back in 2007, Palm had a great idea for a netbook. That was a largely unfilled niche at that point, and Palm thought that the 10" Foleo would make killing. It didn't.
Palm never released the Foleo, because as the ship date approached it became more and more obvious that it cost too much (the Asus eee701 cost half as much) and not very many people wanted to buy one. In some ways, the Foleo was like the TouchPad. It had a decent design with several clever features but died due to poor mrketing, app support, and the fact it simply cost too much.