Perpetual Inventory Using LIFD Beginning deventery, purchases, and sales data for portable game players are as follows. The business meintains a perpetual inventory system, costing by the last-in, first-out meshod, the units with the MiGreR unit cost first in the Cost of Merchandise Sold Unit Cost column and LoWER- unit cest frat in the Inventory Unit Cost column. Perpetual Inventory Account LIFO Method Portable Game Players