Discussing the $350 price of a ticket for one of her concerts, Barbra Streisand said, “If you amortize the money over 28 years, it’s $12.50 a year. So is it worth $12.50 a year to see me sing? To hear me sing live?” Under what condition is it useful for an individual to apply Ms. Streisand’s rule to decide whether to go to the concert? What do we know about the discount rate of a person who made such a purchase?