although I do think EBay
distorts prices because it often gives a false impression of the rarity of
an item (ebay value != market value, in other words).
This rule of thumb applies to any auction, not just Ebay. Many
collector magazines for all kinds of antiques have little statements
(disclaimers?) basically saying this. And, if you attend a real live
auction house after a while, you will see that a large portion of the
bidders (and winners) are dealers, not the end users (collectors). You
will also see what the dealers will pay, and how two collectors can
fight. Basically, a free for all, value wise.
However, one can get a good guess about what one can get for certain
things at auctions.
--
Will