A chair manufacturing fabrication workshop received an order for 50 units of chairs. To make 1 unit of chair, a fee for a stainless pipe of 80,000 rupiah and a stand of 20,000 rupiah is needed. To complete the entire order, it is estimated that it will consume 500,000 rupiah of electricity, 200,000 rupiah of welding electrodes, and other costs of 250,000 rupiah. The labor fee is charged to each seat unit of 50,000 rupiah. From these costs group into each type of cost, then calculate the total manufacturing cost! It turned out that the booker wanted to increase his order. The head of the company asked for the calculation of costs for the amounts of 60, 65, 70 , 75 and 80 units. It is estimated that every additional 5 units of seats, the fixed cost will increase by 10,000 rupiah. Calculate the average cost, total cost and marginal cost for the number of units requested by the leadership!