Here in Georgia, our small AA, now 1A-D1, HS football coach was making 90k in the early 2000's. We haven't sniffed a state championship game since 1969. I'm sure every coach in 4A and above is north of 100k. 3A and under is where it gets to hits or misses. But, believe it or not, most of the HC have advanced degrees which get a boost in their base pay. Then you have the supplemental income for being HC. Then the incentives for region runner ups & champions. Plus state runner up & champions incentives. ONLY then does the booster pay come into effect. Don't forget the local Ford dealership in these small towns giving the HC a truck to use while he is employed.
My now ex-wife told me back when we were dating and I was a graduate assistant college coach, that I picked the wrong sport to be good at and become a coach.