It is hard to justify a $150 surcharge if you're using a tool that costs less than that (of course, knowing how to use the tool is a skill worth far more, but most people think it is as easy as putting it in the lock and pressing a button). I'm reminded of the apocryphal tale of the mechanic who, after some um-ing and ah-ing, hits the engine just once with a small hammer and fixes it. He presents his bill for $100, and is asked to justify it, so produces:
Hitting engine with hammer - $1 Knowing where to hit - $99