Tom was tired of running his business and was looking for a buyer so he could retire before the winter. Bill wanted to buy the business, but needed another month to raise the necessary finances. Tom said to Bill, "Look, for $5,000, I'll give you an option to purchase in 30 days, but if you're not ready to buy then for $50,000, I'm going to sell it to Dan." Bill paid Tom the $5,000. Thirty days later, Bill appeared at Tom's door with $45,000. Tom said, "Sorry, I'm going to sell it to Dan. I said the price was $50,000." Bill was confused, and sought legal advice. What advice would the lawyer provide to Bill?