Again, you are one of those confused by the fact that you can reveal your bid before the auction closes. This fact makes many people (not just you) think of eBay like a competitive bidding auction, but it is not. The way they do that fools you into thinking it, but just repeat it again and again. It isn't that. It's a sealed-bid (or rather a strange slightly unsealed bid), second price auction. If a sniper beats you it's because the sniper knows what eBay is, and you got tricked into thinking it was something else. You just have to get the concept of the back and forth bidding auction out of your mind. This is hard because of how eBay sets it up, but you have to do it.

Sealed-bid second price auctions are competitive too. Almost all the major auction forms are competitive and form efficient markets when there are lots of buyers and sellers. They all have different balances between buyer, seller and auction house and there is no one right balance.