I've been putting some lots up on ebay in the past year or so and in the past month or so seem to have acquired a buyer who consistently bids on each lot. These aren't fabulous marbles, but good for a starting collector and in nice clean condition. He obviously knows how to bid and keep out other bidders by getting in the first bid, then if there is more than one bid, it just stays on the starting minimum. Does this mean that subsequent bidders decide not to go up over whatever he has set for his maximum, so it just stays there at the bottom? I'm confused about this. OTOH, I'm glad to sell them but on the other, would like to get more than the minimum. I've been setting a very low start. Any advice?