You're right about the cost of producing the panels. All good points for me to think about.
In the class called Engineering Management or Engineering Economics, probably an upper level course, they go into cost of engineering projects, project lifetime, useful real-life considerations that engineers need to know about to be effective project managers. It is one thing to design a power plant or a locomotive, quite another to design and build something affordable that can be operated economically over a 20 year lifetime. The engineer, after all, has to interface with reality.