I know your joking, but I feel like this is an important thing that's often lost on people. The other day I got in a bit of an argument on oDesk because I turned around a job too quickly. The guy didn't think it was worth the price we agreed upon. I had to explain that that wasn't a 15 minute fix, that was years of studying in university, and years of trial and error, and hard won experience to know how to solve his problem in 15 minutes.
I'm not joking at all. I had a consulting customer once that had a problem; I asked him a couple of things on the phone that he insisted he'd checked, and he pleaded that I come to Chicago in person and take a look, when I lived in Southern Indiana at the time. I said I'd bill him a day (which was generous; the whole thing cost me 13 hours).
Turns out that yes, one of the (trivial) things I had asked him about, that he'd said he'd checked, hadn't been checked. He was up and running in half an hour.
Then he didn't want to pay for a whole day because it had been so easy. But he did, in the end, pay for a whole day.
Yeah... I am dead serious that I did not feel ripped off. Learning a lesson is worth every penny, in itself. Having someone else risk a spark near a gas source is a special kind of cost. :)
He stiffed me in the end...