eBay sniping

Not remotely? Is almost exactly like a sealed bid. Those price changes during the auction mean absolutely nothing, as the final price is determined in the last 5 seconds (at least in the majority of cases). Nobody takes those prices changes during the auction seriously, its like people talking before an auction, discussing what the items are worth, but nobody really tells you what they really think its worth. That comes in the last 5 seconds. Since the other bidders have no practical way to counter bid those bids entered during the last 5 seconds, ebay's auction model can accurately be called a "sealed bid" auction format, with the highest bidder paying the second highest bid. If you change ebay's format to extend the auction time after each bid, then I agree its not a sealed auction anymore.