Salary
Average Salary: $88,000
Expected Lifetime Earnings: $3,673,824
Unfortunately, not all schools are created equal.
A school principal makes somewhere in the neighborhood of $88k a year (source).
Your salary depends on what kind of school you're in charge of and where that school is located. For instance, the principal (or headmaster) of a fancy-shmancy private school in a ritzy area is going to make more than, say, the principal of a public school in a more challenging neighborhood.
You can also pick up a little extra dough by giving talks at conferences, or writing books about your experience as an educator. Both are very common for people in this position.
While a potential six-figure salary sounds tempting, just know that you're going to have to earn every cent of it.