As the name of the button suggest, The Buy It Now (BIN) button allows you to purchase an item right away before the bids reach the BIN price.
The BIN button is particularly useful if there is an item that you want very much and prefer to lock in the purchase at a fixed price rather than take the risk of the cost going well above the BIN price as the auction progresses.
No matter the value the BIN is set to, the auction bidding will operate in the same manner. If you wish to bid, enter your bid in the place bid field and click bid now.
The BIN button will no longer be available when the current bid crosses a reserve price, which the seller determines. The reserve price is usually a set percentage of the estimate value; typically it is set to 50% of the estimated value. Once the current bid crosses the reserve price, the BIN button will disappear and bidding will have to continue until the auction closes naturally. The percentage used to calculate the reserve price may vary from item to item, based on the sellers discretion.
If you click the BIN button when available, you will automatically be declared the winner of that auction. Once you have used the BIN no cancellation will be accepted and it will have to be paid within 48 hours.