I avoid sniping by simply entering the MAX amount that I would be willing to pay. I've had some eBay auctions where I have my max bid hundreds of dollars over the current winning bid even if it is as little as $20.
It is simply irrelevant what someone else is willing to pay even if they win by $1. You should have allowed yourself a greater cushion.
Nobody knows what their max bid is. We're humans, not robots. What our max bid is changes depending on the day of the week, how hungry we are, what the weather's like, whether we just got our paycheck, and whether we're fighting with our significant other, among other things.
Also, if I decide my "max bid" is $300, does that mean I really wouldn't pay $301? Or $302? People don't have hard limits. Computers do; that's why Ebay's computers will only bid up to what you say and then stop. But the human who came up with that number has no such restriction. So if I put in a max bid of $302, does that mean I wouldn't pay $303? Or $304? Where does this end? It doesn't.
The whole idea of a "max bid" is the fatal flaw of Ebay's system, and why people still complain about sniping despite all of Ebay's attempts at tamping down the criticism over the years. There's just no such thing as the "max amount" a person would pay for something. There's only a max amount at this particular time and under these particular circumstances, and all that changes literally from minute to minute. That's why real auctions work the way they do. The person willing to pay the most *at that moment* is the winner, and the auction just goes on until that winner is determined, not on a set time limit.
You have to work within Ebay's system if you want to get the stuff they have, but that doesn't mean it's not a stupid system. It is. It goes against human nature, which is why these kinds of complaints will come up again and again, forever, until they change it.