right now, i teach and coach head xc boys and girls, assistant indoor and head girls/ boys and girls distance outdoor. I make around 12.5k per year for the coaching, on top of my teaching. of course, having to teach really cramps time for proper preparation, but I make do well enough.
I will retire in around 17 years. at that time, I'd probably take a small school coaching gig for 10 to 20k. No problem. Would just love to have that as my only responsibility in life.
A lot of the highest paid d3 coaches probably teach a handful of classes, as well. I know all the coaches at the junior college i attended had to teacher several sections of classes. All cake coaches. and most of them taught poorly. But there was the occasional coach who took pride in their job, or they were just so naturally good at teaching the subject matter that they were good without trying.