A few years ago, one of my first business coaching sessions was with an entrepreneur who had spent a year and a half in development. He’d given up a well-paid job and spent about $25,000 on developing an App. He had no real business plan. When I pointed out that he had notionally invested about a quarter of million dollars on the App, he drew a deep breath of entrepreneurial fatigue, and said disheartenly, “Well, I suppose so.”

This back of the envelope calculation was done as follows: see calculations and read more here.