GSC bookstore is planning to publish a special secret book "How to make A without efforts in Operations Management?" Fixed costs are $20,000 per year, variable costs per unit are $10, and selling price per unit is $20(i.e., the break-even volume is 2,000 units). What price must each book (unit) be sold for to obtain a yearly profit of $20,000? Assuming that the estimated demand is the same amount at the break-even.