I've sold cartridge only copies (with heavy label damage at that) for up to $60+ on eBay. I sold my complete copy last November in the Buying and Selling forums here for $180. I wouldn't pay over $200 for a complete copy because no matter how the trends go and how much people want to overpay, that's the maximum you'd ever get back for it.
Also the only reason I sold it was because I needed mad cash to drop WAY too much on a sheet of old acetate (that'd be an animation cel) for my girlfriend for Christmas last year - no regrets.
I originally paid $90 for that complete copy so I doubled my money. For the loose copies, that beat to snot one that ended at $54 ran me $6 at a flea market.