In our house, we call the "saving money by buying stuff" as "Ginger math", after a friend of Ella's.

There was a party at our old place (that you helped us move into) where our mutual friend B was explaining to another guest about what Ginger math was.

Ella and I looked at each other with a "do you wanna tell her?" glance. I won, so I said "B, let me introduce you to Ella's friend Ginger." I was vastly amused, as was Ginger...