Foamsoft sells customized boat shoes. Currently, it sells 10,000 pairs of shoes annually at an average price of $70 a pair. It is considering adding a lower-priced line of shoes which sell for $50 a pair. Foamsoft estimates it can sell 5,000 pairs of the lower-priced shoes but will sell 100 less pairs of the higher-priced shoes by doing so. What is the amount of the sales that should be used when evaluating the addition of the lower-priced shoes?