At any time you have been outbid. If you are the successful highest bidder at close of auction. There is no restriction on the number of times you can bid on an item before the auction closes. The time left for the auction to run is shown, both on the item page of the auction site, and also alongside any items shown if you do a search from the home page. You are not charged for this service.
All bidding is FREE from auction charges.
A bidding form will be found below all items that have been entered for auction and bidding is very easy to do. The bidding form tells you what to do as you go along. At this stage, if you are a high bidder, you will receive an email confirming your bid. The seller will have described on his auction page how he wishes to be paid and how the item will be shipped. You can see this before bidding, in case the seller's conditions don't appeal to you.