Swiping! Love that move.
Anyone can do that, place a bid in the dying seconds, and hope it goes through. Take note that you won't be alone in doing it and only one will succeed. What I do is bid just a tad higher than the regular going price for that item (remember, there's no time to react). I stalk eBay for weeks for that same item and visit Amazon and other stores for regular brand new prices to make a qualified estimate. I've done it a lot of times when I was still collecting lenses.
It's all hard work that ends up with a steal if you play it right so stop being annoyed. If you really wanted it, why didn't you bid higher? You can always outbid yourself, right, because that's what I do if I really wanted an item - I double the regular going price right from the start (and watch them give up). Remember, it doesn't matter how long you were at the top, what matters is in the end, the highest bid wins.