I don't think he relisted it. Someone probably made him an offer and he figured out how to take advantage of it.
Ebay and paypal are getting sneaky. They will not give you a bidders email anymore even after purchase. I think you can request it though.
One way would be to cancel the original price, then set a huge BIN price and then have the seller make a higher offer if they wanted it for a certain price. Problem is ebay can see all the back and forth dealings if you use their messaging. I lost out on about $100 because someone made me an offer after someone else had already placed a bid on something I was selling. I didn't check the box that said offers accepted, but once there is a bid on it, they won't let you do this anyway.
