In many cities, discount clubs are popular. For a fixed annual fee (paid in advance) one can purchase goods at 85% of their listed price (in other words, 15% off the list price); otherwise, one pays the list price. Suppose that the annual fee is $250 and the interest rate on your savings account is 4%. Finally, assume discount club's list prices are the same as any other store, and you plan to spend $1000 over the coming year at this store. (Hint: the interest represents an opportunity cost of purchasing a membership).
