Smith Company sells its products at $500 per unit, net 30. The firm's gross margin ratio is 40 percent. The firm has estimated the following operating costs: Activity Cost Driver and Rate Sales calls $ 400 per visit Order processing $ 100 per order Deliveries $ 50 per order + $0.50 per mile Sales returns $ 60 per return and $3 restocking per unit returned Smith Company has gathered the following data pertaining to activities it performed for two of its customers XBT 10 500 NINTO 2 2,000 Number of orders Number of parts per order sales returns Number of returns Number of units returned (per return) Number of sales calls Miles per delivery Shipping terms 4 40 6 10 FOB, Pactory 10 50 10 20 POR, Destination What is Smith's total sales-sustaining cost applicable to XBT os a customer