I'd say it's worth about 10 iPods at least - to me. Since I already have two however, a third isn't worth quite as much.
But how much you'll get is all dependent on market factors. You could try the eBay route and simply see what that market will bear.
Look in the forsale forum and also click through past eBay auctions to get a feel for the market. Most people out of the loop won't immediately "get" the empeg, so their perception may limit the amount of money they're willing to spend. You have to find the small percentage that "get it" but don't already "got it."
There's at least one up for sale for UKP right now, so use that as a guide. It's priced high, but I think fair. I sold a stock one about 2 years ago for just under CAD$1000 with a 10GB drive (new in box though).
Bruno