It’s funny reading this, because the way I heard the story was as a railroad story.
The train engine wouldn’t run. The expert was called, he arrived, and after inspecting the train engine, knew exactly were to apply a little bit of oil to make it run again. His bill was challenged as being overly expensive, and he countered with them paying for the knowledge of where to apply to oil, not the oil itself.
There’s like all these different versions of the same philosophy of the story