Looking at something on eBay (not super rare or amazing)- one bid already at say £10, a week before the auction finishes. So I bid £11 and I’ve already been outbid. I go again and again and then at £16 I am the highest bidder. Right before the auction ends there’s a flurry of activity and that pushes the price up even higher. Or something is on at £10 with one bid, so I try £11, £12, £13...still not the highest bidder so leave it there. Maybe there’s an obvious explanation for this but why do people put in maximum bids so far in advance of the auction ending? Surely this just bumps up the price for them?