ignore tax portion if wanted and pls explain the solution

Problem 2 The Hopedale Inn invested in a ten-acre plot of land for future development twenty years ago. It purchased this land for $100,000 and it could be sold today for $500,000. The Hopedale Inns average and incremental tax rates are 22 percent and 30 percent, respectively. The Inn is considering building a new lodging facility on this land. Reguired: What is the opportunity cost of this investment? Problem 2 The Hopedale Inn invested in a ten-acre plot of land for future development twenty years ago. It purchased this land for $100,000 and it could be sold today for $500,000. The Hopedale Inns average and incremental tax rates are 22 percent and 30 percent, respectively. The Inn is considering building a new lodging facility on this land. Reguired: What is the opportunity cost of this investment