If you publically post evidence against a dealer then make sure its bullet-proof.
Word of mouth does the job quite well, and is less problematic.

I reckon its hard for dealers selling to collectors vs people who just want 1 pin for the rumpus room. Collectors demand more attention, and demand the product to be a higher standard. AND of course we want all that for a cheap cheap price. If I see a dealer starting a pin cheap on ebay then I have no high expectations of it.
Its simply on ebay to grab attention, and to lure the mum and dad buyers into the shop. That, and to flog a machine taking-up space needed for a more saleable pin.