Someone offers to sell you a concert ticket for $50, and you reply, “I’ll give you $40,” The seller refuses to sell at the lower price, and you say, “OK, OK, I’ll pay you $50.” Clearly, no contract has been formed, because you made a counteroffer. If the seller has changed her mind and no longer wants to sell for $50, she doesn’t have to. But is this fair? If it is all part of the same conversation, should you be able to accept the $50 offer and get the ticket?