I've always thought that there are two types of seller on eBay when it comes to finding one of their old computers:

The type who thinks his old *insert name here* is old and therefore useless who will price it low.

The type who thinks his old *insert name here* is old and therefore extremely rare who will price high- optimistically high!

I don't think the Macintoshes that priced highly sell anyway; the sellers still seem to list them!