If you think you've got the market values all worked out, high prices for Apple clones, SX-64's no longer selling for $150, then how about $511 for a Simon handheld game ...
http://www.trademe.co.nz/Browse/Listing ... =523192542
Another boxed one sold for $150 http://www.trademe.co.nz/Browse/Listing ... =523192542 . That's a $50 note higher than what the normal maximum would be as well.
I say it too often, but promoted auctions on trademe get the looks and the bids (for anyone considering selling their vintage computer items) provided you use enough hyperbole.