A turn of the screw

One day the main production line in a huge factory broke down. The production stopped and the owner was loosing millions a day. He tried many ways to repair the broken line, but nobody could fix it.

Eventually he finds an expert in the production line - the engineer comes, checks the machinery, takes a screwdriver out of his pocket, tightens one screw, and the factory springs back to line. Happy, the owner asks how much he owes. The expert presents a bill for $10,000.

Outraged, the factory owner asks for a detailed bill.

The experts takes the bill back, makes a note on it and gives it back to the owner. The bill now states:

* Turning a screw: ................................... $       1.00
* Knowing which screw to turn: ............... $9,999.00

------------------

An expert is not expensive, it's priceless!