For most construction projects, Foress Heating and Cooling buys sheet metal and forms the metal into heating/cooling ducts as needed. The company estimates the costs of making and installing ductwork for the Kerry Park shopping mall to be as follows: Materials Labor to form ductwork Labor to install ductwork $32,500 4,220 10,790 Miscellaneous variable installation costs 1,430 Fixed costs allocated based on labor hours Total cost 2,950 $51,890 The fixed costs relate to the company's building, equipment, and office staff. The company plans to bill the Kerry Park developer $68,000 for services. Foress is currently behind schedule on other projects and is paying a late penalty of $1,229 per day. Walt Bradley, the owner of Foress Heating and Cooling, is considering ordering prefabricated ductwork for the Kerry Park job. The prefabricated ductwork will cost $39,490 (including the cost of sheet metal). If Walt buys the prefabricated ductwork, he'll be able to reassign workers to another project and avoid five days of late fees. Should Foress make the ductwork or buy it prefabricated? Net incremental of buying will be $ Foress should the prefabricated ductwor