2nd year master's student (absolutely hate it) with prior Higher Ed work experience here!
You can apply for any non-academic position on a college campus or allow you to work in government (I'm currently researching for the DOE), or for an education non-profit, for the most part. This includes consulting, advising, student affairs, Greek Life, housing, really anything on campus that is not a professor job - it just depends on what you want to do.
I feel the master's is highly marketable because you're able to see a university/organizational system from a perspective that many in education cannot, nor do many (mainly in my experience with K-12) understand higher ed. A lot of programs have a social justice focus which would allow you to work in a lot of diversity-type of programming (HR, Corporate Consulting, etc.). There's currently a big push for educational and family relations, and pre-college outreach programs so that could be an option for you as well.
YOU SHOULD NEVER PAY FOR A STUDENT AFFAIRS DEGREE. The majority of programs require you to have an assistantship or fellowship which covers your tuition and provides you with a stipend. If a program offers you 0 funding, you can sometimes apply for assistantships or jobs after you've been admitted but the full funding won't be there and you'll still have to take out loans. At the moment, the cap on unsubsidized loans is $20,500 for graduate students at a 7% interest rate, so that's not fun.
To be an administrator, you typically need a doctoral degree. You can get pretty far with a master's but any promotion will require you to have a doctoral degree.
Start at an entry-level student affairs job and work for 3-5 years at minimum. I worked before going to back to school full time and my work experience has proven to be far more beneficial in my program. Majority of my classmates are fresh out of undergrad and really have no understanding on how higher ed works, and everything we're learning is conceptual to them as they cannot piece things together within the organization. If you work at an institution with a master's program, there is often employee tuition waives so you can go to school for free. Granted, you may need to spend 3-4 years in a program, but it'll be free! Higheredjobs is a good place to start but do not apply through them - go directly to the institution's website to apply for the position. Higheredjobs may not update their listings frequently so you may miss an application deadline.
When looking at programs, look at the faculty's titles. Faculty members who are professors are going to be researchers and thus, your program would be geared towards students who are interested in the research and doctoral degrees. Faculty members who are Assistant/Associate Directors, Vice/Assistant Provost positions are going to be practitioners - teaching HED courses will be their 2nd job as running the school is their primary.
The most common question you are going to receive is, "why higher ed when you have a degree in secondary education?" Think about your answer to this. You can be honest and mention that you learned a lot about yourself through your student teaching and realized that secondary education was not going to be your best fit but you still want to stay in education.
Let me know if you have more questions!