The Nansen Company uses the perpetual inventory system and the moving - average method to value inventories. In August, there were 10,000 units valued at $30,000 in the beginning inventory. On August 10, 20,000 units were purchased for $6 per unit. On August 15, 24,000 units were sold for $12 per unit. The amount charged to cost of goods sold on August 15 was: