Does the listing have a BUY IT NOW icon? Click on it and pay the BIN price. This will end the auction.
If there is no BIN or Best Offer icon, the seller has decided that he will get his best price by allowing the auction to complete itself. He will not entertain other offers and you can be pink-slapped for making them.
If the seller indicates that he has multiple items, you can use Contact Seller to ask him to set up a private listing for you at the price and shipping the two of you agree is acceptable. If he agrees, suggest that he use your user ID as the title of a fixed price listing. This is the most reliable way to keep other bidders away.
