Joseph and Melanie, while having dinner, attempt to negotiate a deal for Joseph to sell his house to Melanie. Joseph offers to sell the house for $575,000. Melanie counters with an offer of $550,000. Joseph says he'll think about the counteroffer and respond the next day. Joseph sees Melanie the next day and tells Melanie that he does not accept her offer. Melanie says she understands, but returns an hour later and states that she accepts Joseph's original price of $575,000.  

In the hour since Melanie was gone, Joseph received an offer of $600,000 for his house. Knowing that you have studied the elements of a contract under the commonn law and the statute of frauds, Joseph approaches you and asks if he must sell the house to Melanie for $575,000.  

Please respond to Joseph's inquiry in one or two paragraphs.