Your buddy in mechanical enginnerring has invented a money machine. The main drawback of the machine is that its slow. It takes 1 year to manufacture 500$. However, once built, the machine will last forever and require no maintencance. The machine can be built immmeaditiely, But it will cost 5000$ to build. Your buddy wants to know if he should invest the money to construct it. If the interest rate is 12% per year, What should your buddy do?

NPV=????

What should your buddy do?