Last year, Ariel earned $40,000 selling real estate, but she now sells children's shoes.
The return to entrepreneurship in the children's shoes industry is $12,000 a year.
During this year, Ariel bought $15,000 of children's shoes from manufacturers and sold them for $60,000.
Ariel rents a shop for $7,000 a year and spends $2,500 on utilities and office expenses.
Ariel owns a cash register, which she bought for $2,500 with funds from her savings account. The bank pays 5 percent a year on savings accounts.
At the end of the year, Ariel was offered $1,600 for her cash register. What is Ariel's implicit costs?