Feller Company purchased a site for a limestone quarry for $100,000 on January 2, 2019. It estimate that the quarry will yield 400,000 tons of limestone. It estimates that its retirement obligation has a fair value of $20,000, after which the land could be sold for $10,000. In 2019, 80,000 tons were quarried and 60,000 tons sold. Costs of production (excluding depletion) are $4 per ton.

Required:
1. Compute the depletion cost per ton.
2. Compute the total cost of the inventory at December 31, 2019.
3. Compute the total cost of goods sold for 2019.