I agree with Charles. You'll note all the bidders on the first auction are new eBayers with low feedback. They likely aren't chip experts and probably bid because this was a chip from a place they recognized, it was old, it was a commemorative, and the pictures were detailed and showed both sides.

I know it's a pain to provide good graphics, but I've found it does make a difference in the bids you get. I also recommend you NOT use the free picture service that eBay offers, but upload to your own server, show the chip at about 150% of actual size, and don't compress too much when you save your .JPG file. Something in the 20KB to 50KB file size range is a good compromise and doesn't take too long to load even on a dialup connection.