Buy it now is a special feature which can be added by the seller of a listing. Please checkout the instant purchase icon near the listings title in search results. If you are the seller and if you add the buy now tag at the time of listing, you'll be able to specify a price at which you are willing to sell the item immediately. For buyers this gives them the opportunity to buy the item immediately and need not wait for the auction to get complete. The buyers can also opt for normal bidding process.
Tips for buyers who use buy it now:
Decide whether you're willing to buy the item for the Buy It Now price. Please remember, shipping and handling charges are not included in the Buy It Now price. You may need to contact the seller to determine the total price of the item.
To purchase the item via buy it now, click the Buy It Now button at the bottom of the item page. Now, you'll see a Buy It Now confirmation message continue only if you want to purchase the item.
Once you have confirmed the item is yours. Pay for the item using the available payment methods chosen by the seller, and the seller ships it to you.
When it's part of an auction-style listing, the Buy It Now option is only shown on listings until an item receives its first bid, or, for a Reserve Price Auction, when the reserve is met. This means that when you see an item has both a Buy It Now price and a first bid price listed, you will need to act quickly!