PROBLEMS 21-Debbie Corp. sells customized baekpacks. Currently. it sells 20.000 backpacks annually at an average price of $80 each. It is considering adding a lower-priced line of backpacks that sell for $60 each. The firm estimates it can sell 10.000 of the lower-priced backpacks but will sell 3,000 fewer of the higher-priced backpacks by doing so. What is the amount of the sales that should be used when evaluating the addition of the lower-priced backpacks