Choco Inc. uses a perpetual inventory system. If Choco Inc. uses the LIFO method, how much is the cost of goods sold (COGS) for September?

9/1 Beginning inventory 300units @ $7.7

9/5 Sales (price $20/unit) 150units

9/15 Purchase 500units @ $11.3

9/22 Sales (price $20/unit) 400units