‘Look after the pennies, and the pounds will take care of themselves’ my grandmother used to say. But perhaps you’ve heard the old story that if Bill Gates sees $100 on the ground, it will cost him more to bend down and pick it up than to keep on walking?
It’s the same kind of logic used to justify domestic services:
‘I earn $30 an hour. Why should I clean my own house when I can pay someone else $15 to do it?’
On the surface, this seems to make (financial) sense – You earn $30, give half to the cleaner or the lawn mower, and still come out with a profit.