Sometimes you find that perfect item, it's only 99c and you straght away put $100 on it and keep a close eye. Nevertheless, it's still 7 days away until auction close, and on the 3rd day, someone has outbid you $100.50. You've got to have this item, so you put $150, and by the time the auction closes, you haven't won the item, and it has sold for $300. Never mind the item sells brand new for $350.
To get the item cheaper
What you need to do is find the item and WATCH it. Do not bid. Just watch. Chances are, the item has been bid on, lets say, to $50 and it's a day before auction close. Still, as hard as it is, do not bid.
Take note of the auction close time and be there around 5 mins prior. Chances are, the item has gone to around $100. If it is a popular item, there will be a lot of people watching it. Set yourself a maximum dollar to bet to, and with 1 minute to go, place bets in $50 increments.
So, if the item is at $100, bet $150. If you are outbid, place the bid to $200. Once here, if you are the highest bidder, refresh constantly right down to zero and you pretty much should win each time. Just make sure that if you really want the item, you place a solid bid as close to auction close as possible. You could pick up your $350 item for $200 or less using this method.
I know, because I've done this many time.