Or...the seller want's to artificially inflate the value (current bid amount) & interest in his/her coin(s) by having someone he knows who also is on ebay, place bids on his coins, in hopes that someone else will come along and outbid his friend. I think they refer to it as shill bidding. I've had an account with ebay since 2004, purchasing more then selling, and I've seen so much stuff going on with that site. It's to the point now I don't even look at auctions that have reserves. I will wait for what I am looking for to appear in a "buy it now" type of auction at a price I think is reasonable.
If you subscribe to Ebay Bucks, then you know that the next period to cash them in begins on July 1. I have a number of BIN listings I'm watching that all end after that date, so I'll be getting a big discount over the seller's price on a couple of these just by being a little patient.