Subject to minimum increment rules, the highest bid wins, not necessarily the one that's submitted last in the auction. The price might go "sky high" depending on the bids placed. For example, if you're sniping with a max bid of $100.00 on a $25.00 item and another sniper bids $97.00, you're stuck. A few rules to follow:
1. Always bid your maximum. Chances are you won't need that much, but if you do, you'll be glad you bid it all.
2. Don't worry about other snipers or who gets in the last bid in an auction. The winner is still going to be the person with the highest bid.
3. Be careful about the lead time you allow. For instance, Sunday nights are eBay's busiest time and a snipe with only 7 or 8 seconds lead time has a good chance of not being registered by eBay in time for the close of the auction. Allow 15-20 seconds for Sunday night bids and for any auctions that end on the exact hour, half-hour, or quarter-hour (XX:00:00, XX:30:00, XX:15:00, and XX:45:00).
Good luck!