Required information In October, Nicole eliminated all existing inventory of cosmetic items. The trouble of ordering and tracking each product line had exceeded the profits earned. In December, a supplier asked her to sell a prepackaged spa kit. Feeling she could manage a single product line, Nicole agreed. Nicole's Getaway Spa (NGS) would make monthly purchases from the supplier at a cost that included production costs and a transportation charge. NGS would keep track of its new inventory using a perpetual inventory system. On December 31 of last year, NGS had 20 units at a total cost of $5.90 per unit. Nicole purchased 20 more units at $7.90 in February. In March, Nicole purchased 20 units at $9.90 per unit. In May, 40 units were purchased at $9.70 per unit. In June, NGS sold 40 units at a selling price of $11.90 per unit and 50 units at $11.10 per unit.