Donna, a 16 year old girl, entered into negotiations to purchase a hunting cabin in the mountains from Josh. Neither party was represented by an attorney during the negotiations. Josh's asking price for the cabin was $60,000. Donna's first offer for the cabin was an extreme "lowball offer" of $5,000, which she really intended as a way to get the negotiations started. Eventually, they agreed on a purchase price of $50,000 and shook hands on the deal. The negotiations were witnessed by various third parties, all of whom stated that the agreed upon price was $50,000. John had a friend of his type up a simple contract memorializing the deal. However, the friend made a typographic error and stated that the purchase price was $5,000. Josh and Donna both signed the contract. At the closing, Donna tendered $5,000 and demanded the deed in accordance with the written contract.

Question: Must Josh sell the cabin for $5,000? Why or why not?