You own some nice shoes which you use once per week on date nights. You bought them **2** years ago for $**500**. In your experience, shoes used once per week last for **6** years. So you expect yours to last for another **4** years.

Your younger sister said that she wants to borrow your shoes once per week. With the increased use, your shoes will only last for another **2** years rather than 4.

What is the present value of the cost of letting your sister use your current shoes for the next 2 years?

Assume: that bank interest rates are **10**% pa, given as an effective annual rate; you will buy a new pair of shoes when your current pair wears out and your sister will not use the new ones; your sister will only use your current shoes so she will only use it for the next 2 years; and the price of new shoes never changes.