A construction company is bidding on a project comprising five high-rise buildings to be erected one after the other. The company considers the purchase of a set of advanced, hydraulically operated tunnel forming systems for $20/sf. The forms are to be used 200 times for the forming of 1,000 sf of walls and 1,000 sf of slabs per use on a series of residential buildings over a period of 4 yr, and then they will be sold. Salvage value is expected to be 10% of original purchase price. No maintenance costs are expected. Labor productivity is estimated at 0.025 labor hr/sf. Hourly wages are $22. Consider 5% annual interest rate. What is the average formwork cost (material