If you want to snipe too, and don't want to do it manually:
http://isnipeit.com/
But, as mentioned before, the way to bid on eBay is to always Bid Your Max. Snipers bid this way too, as they only get one shot at entering a bid. Always bid the absolute most you are willing to pay for an item, you will still only have to pay the least amount it takes to keep you ahead of the second highest bidder.
Pretend eBay only allows you to bid once, and figure out what you bid would be in that situation... Then add a little bit extra.
Never bid in round numbers. If something is worth 25.00 to you, bid 25.33 or something.
You don't have to bid last, you just have to bid highest.