I both buy and sell on Ebay as a buyer I use several tactics to secure the items I bid for at the lowest price I can.
1) Early Bidding this tactic has the positive affect of chasing away the bargain hunters and reduce the amount of people bidding on the item.
2) The snipe bid this involes placing your bid at the last possible moment and hopefully stealing the item at a bargain price.
3) Combination bidding which is a combination of the above 2 the first bid is a small bid to a) show there is interest and scare the bargain hunters away b) allow you to get a feel for how much interest there is in the item. There is also another reason for this as a seller I will often start items at a very low price giving buyers a good chance of snacthing up a bargain if there no bids after a few days the price is increased to the minimum amount I can afford to sell the item at. Having an early bid can a lot of times win you an auction at way below wholesale price. Most bargains I get on Ebay is done through combination bidding.