There's a story/joke about a company that has a large, important industrial machine that stopped working. They call in a specialist engineer, who walks up, hits it with a hammer and it starts working again. He then hands the manager a bill for $2000. Incensed, the manager demands an itemized receipt because this was outrageous for something that took 2 minutes. The engineer kindly obliges: hammer $5, knowing where to use the hammer $1995.