An MA in Art History will not even get his foot in the door for an interview at any 4 year college, as a PhD is necessary in that field.

If he wishes to teach studio art, that’s different. A studio art professor need only have an MFA. But in order to get hired at a university, besides the MFA, he would need to have a very strong portfolio, including some juried shows, and would need to have studied with some well-known artists with specialties in his medium.

University (and even community college) professors do not get teaching degrees. These degrees are for people who intend to teach primary or secondary school.

In order to earn 70k in studio art, you have to be at least a full professor at a university in a non-urban area, or at least an associate professor in an urban area or a very prestigious university. It usually takes 6 years after hiring to be promoted to associate, and another 5-8 years to be promoted to full. But promotion is completely contingent on publication or other measures of success. In studio art, that measure of success is more participation in juried shows, commissioned works, and one-person shows at galleries and / or museums.

1. A PhD and postdoctoral experience in science or engineering (8 years after the BS is typical).

2. Tenure at a research university (5 years is typical).

3. External grants that provide overhead back to the university.

One way to make more money is to teach summer school. Summer school usually amounts to about a 20% increase on an annual basis. But that only brings 50k to 60k, not 70k.