I agree that if financial gain is the objective (and there's no reason why it should not be), then eBay would for sure be the way to go.
I wasn't all that sorry to see mine go. Sure, it's an oddity but it's noisy as hell, hard to use, heavy, stupidly designed, and is really ugly and kludgy looking - especially in comparison with the flawless lines of the Kirby.
The one thing I thought was kinda cool was the rheostat-controlled motor speed.