Real auctions don't tend to have arbitrary time stamps cutting off each item, do they? As long as people are still bidding, it continues. And you are all there when the auction is taking place, over a short, concise time period. This is unlike Ebay, where the auction is on-going for many hours or days until some point in time, which often ends up in the middle of the night or some other period where you can't be there to have a final "bidding war" with the other bidders. This is where the whole sniping thing comes in... Sure you can set up an auto-bid value, but its just not the same as being able to decide whether you want to continue bidding past that point or not. Scarcity of said item makes a big difference, naturally. Treating online auction sites like a live auction is inherently flawed.
Automatic sniping agents are not really analogous to hiring someone to go to the auction for you. A better analogy would be a null-sound field that prevents everyone else from being able to talk.
