You have been invited to go to the beach with friends for a week. In order to go to take this vacation, you will have to give up work for a week, which pays $10 an hour for forty hours of work. In addition, you will have to pay your share of the cost of the flat you rent for the week, which is $250. You estimate that meal costs and entertainment costs will be $150 for the week, which is $50 more than the $100 you spend on food and entertainment when you are not on vacation. Use these data to calculate the opportunity cost of going on vacation. What does your decision to go or not go to the beach tell you about how much the week-long vacation is worth to you?