A firm began a mineral exploitation venture during the current year by spending (1) $40 million for the mineral rights; (2) $100 million exploring for the minerals, one-fourth of which were successful; and (3) $60 million to develop the site. Management estimated that 20 million tons of ore would ultimately be removed from the property. Wages and other extraction costs for the current year amounted to $10 million. In total, 2 million tons of ore were removed from the deposit in the current year. The entire production for the period was sold. Compute cost of goods sold under the successful efforts method.