You have received an offer to buy a lease for 1 week’s worth of production (100 ounces) in a particu

You have received an offer to buy a lease for 1 week’s worth of production (100 ounces) in a particular gold mine. This lease will occur in exactly 18 months. It is an old mine, so it costs $400/ounce to extract gold. Gold is trading for $365/ounce today but has a volatility of 40% per annum. The prevailing interest rate is 10% per year. What is the value of the gold mine?