Perry had a computer system that he wished to sell. He contacted Robyn by phone and offered to sell it to her for $2,300. Robyn took a few days to reply, and then wrote Perry a letter that said: "I think the price is too high, but I'll offer you $2,000." Perry received Robyn's letter on February 7, and that day mailed her a reply saying that he thought the system was worth $2,300, and that he would renew his original offer. Robyn received Perry's letter on February 10. On February 13, Robyn mailed Perry a letter that said: "I have investigated the market and have decided to accept your offer to sell me the computer system for $2,300." Perry received Robyn's letter on February 15, but assuming that Robyn was not interested in the system, had on February 11 accepted an offer from Ashok to buy the system at a price of $2,200. Ashok paid Perry a deposit of $300. On February 11, upon accepting Ashok's letter, Perry had mailed a letter to Robyn telling her of the sale. Robyn received that letter on February 14. Robyn immediately phoned Perry and said: "Don't give that system to Ashok. I think it's mine." Perry replied that he had no obligation to Robyn because he had received no consideration in the form of a deposit from Robyn, and had revoked his offer to her