It seems that everyone goes crazy bidding on an item during the last 5 min of the auction. I only bid on items that offer free shipping. They will specify "free shipping". If not then the winner of auction has to pay shipping charges. If you list an item for auction...you will get more bids if you offer free shipping.
You don't need to bid until the end of the auction. It says 2 days 8 hours. That's how long it is until the auction is done. Whoever bids the most at the end wins. You can bit until your credits are gone if you want. If you don't win you get your credits back