Antique Dealer has a mint condition, in-the-box, never opened Stinky Pete the Prospector doll from the popular 1950s television show, Woody's Roundup. Collector, who is a big fan of the show, contacts Dealer to inquire about buying the doll. The two negotiate by telephone, but do not come to an agreement. The next dayTuesday Dealer sends the following signed message to Collector: "I offer to sell you the Stinky Pete doll for $3,750 cash. I will leave this offer open until Friday." Collector gets the message. On Wednesday, Collector calls Dealer to accept, but before he can do more than identify himself, Dealer says, "Sorry, I sold the Stinky Pete doll yesterday. I don't have it any more, so I can't sell it to you." Collector is unhappy and hangs up. The next morning, however, Collector learns that Dealer had not in fact sold the doll, and still has it. Dealer had simply decided not to sell because he heard that the wealthy Konishi Toy Museum in Tokyo might be interested. When he learns this fact Collector calls Dealer. When Dealer answers, Collector says, "I'm calling to accept your offer. I know you still have it, and you promised the offer would be open until tomorrow. I'm buying it." Dealer refuses to sell, however, and ultimately sells the doll to Konishi for $10,000. Collector sues to enforce what he claims is an enforceable contract to buy Stinky Pete. What will both sides argue? What result and why?