Right after the additional inventory was purshesed, the value of the inventory, in dollars, was given by the sum of the previous value (8500) and the total cost of the purchased items:
8500 + 180 + 270 + 77 = 8500 + 527 = 9027
Then, after a certain period, the ending inventory is valued $1,500. So, the cost, in dollars, of goods sold over this period is given by the difference between the value after the purchases (9027) and the final value (1500):
9027 - 1500 = 7527
Therefore, the cost of goods sold over this period is $7,527.