I have had Auction sniper for years, never let me down, and have never had any problems either. I have it set to bid at the last few seconds. You get the first 3 snipes free, after that there is a percentage that they charge if you win.
If you do decide to go with them, please use my ebay id as a refferal:
Badbaja72 you get free snipes if someone reffers you, so sign up and tell your friends, and go win some crap
imp:
Auction Sniper: eBay Sniper and eBay Bidding snipe, bid sniping for eBay