My money philosophy I call opportunity cost, with cash, the choice of what you buy is really the choice not to buy every thing else.
I only buy something on credit as a convenience, paid of monthly. other credit usage ignoring the opportunity cost.
Capital expenditures can be bought with credit as long as the Value of USAGE is equal to or less to then the monthly cost compared to renting.
I didn't really learn this until latter in life. It would have been way better if I could have accepted this early in life.
Art B