Buffy is thinking about opening an amulet store. She estimates that it would cost $350,000 per year to rent the location and buy the merchandise. In addition, she would have to quit her $80,000 per year job as a vampire hunter. 

a. Define opportunity cost. 

b. What is Buffy’s opportunity cost of running the store for a year? 

c. Buffy thinks she can sell $400,000 worth of amulets in a year. What would her accountant consider the store’s profit?

d. Should Buffy open the store? Explain. 

e. How much revenue would the store need to generate for Buffy to earn positive economic profit?