Honesty.com can help you find true bargains on eBay. When you search for a particular item, they show you a current range of prices for that item on eBay and identify the bargains among them. Sometimes the item you're searching for may be too rare for them to identify a bargain price. In those instances, they will simply show you which auctions are out there with no bargains highlighted.
Another site I just LOVE is Woot.com! They pick one item a day to sell at a big discount. This site can be addicting so be very careful. You might just find yourself buying something you don't need just because the deal is so good!