Here's a different slant. Suppose you want the item, and you know what your max bid is going to be. Joe schmo wants it too, and goes in to the end as the high bidder at say, $10. Your max is $15. If you put it in early, Joe decides, hey, he really wants it and goes up to $16. You lose. If you waited to the end, you put in your $15, and get it for $11, since Joe is out of time and can't bid against you at the last seconds. Price stays lower. Some people do get caught up in the competition and will beat your price every time, if given the opportunity to keep bidding. Hence, the sniper system, or just using the kitchen timer. It really can save money.
But against sniper service is you have to give them your ebay name and password, and I am a bit too paranoid to trust a third party.
Timer works for me.
Rich