Hell Perpetual Inventory Using FIFO Beginning inventory, purchases, and sales data for portable DVD players are as follows: Apr. 1 Inventory 76 units $73 10 Sale 59 units 15 Purchase 37 units @ $76 20 Sale 26 units 24 Sale 19 units 30 Purchase 36 units $79 The business maintains a perpetual inventory system, costing by the first in, first-out method.