"Fun" anecdote on this: long ago, I used to teach Ruby and Rails, professionally. One of my old professors emailed me asking if I'd like to come back and teach as an adjunct for a single course the next semester.
The pay for the entire course was the same as our day rate was in industry.
Of course, as an employee, I wasn't making that day rate personally, but that's how far out of whack it was overall. It's really brutal. I would love to teach, but it doesn't make any economic sense: ironically, part of the reason I need the extra money is that I'm still paying off my student loans!
The private teaching industry does seem to be able to charge a lot of money, e.g. the coding schools and the (human) language schools. It's the research-oriented/public schools that don't have much extra money for teaching or simply don't care.
The pay for the entire course was the same as our day rate was in industry.
Of course, as an employee, I wasn't making that day rate personally, but that's how far out of whack it was overall. It's really brutal. I would love to teach, but it doesn't make any economic sense: ironically, part of the reason I need the extra money is that I'm still paying off my student loans!