Well, now that you can buy a factory refurb from Apple for $49 plus shipping ($4 I think) I would say that it isn't worth a ton, but if you aren't going to use it then everything is still worth selling. I'm still undecided as to whether or not I want a 1GB Nano or just a 512 Shuffle. I have a 4G iPod 20GB, but I was looking for something to carry around with me more often ... I really think the shuffle might fit the bill for me the best, but it is hard to just skip over the Nano with it's nice screen and all.
So, I don't know what it would be worth, but I'm thinking maybe $30 to $35 but I could be off.