According to the Ph.D. Project, it isn't uncommon for a Ph.D. program to delay billing you until after graduation. In addition, Ph.D. students frequently are reimbursed for their tuition (at least partially) when they work as research and teaching assistants. In some cases, they can teach entire undergraduate courses on their own. Because of these opportunities, doctorate debt can be much lower than debt accrued from undergraduate study.
Starting salaries for business instructors with doctorate degrees can reach six figures, not counting the additional compensation for those professors who choose to research or teach during summer sessions. Salaries vary by location and institution, but a tenured position at a well-respected school can be a high-paying job.
Although you'll need to attend faculty meetings and set aside time for student guidance, the work schedule of a college professor involves a lot of freedom. This can be more comfortable for those who dislike the rigidity of a 9-to-5 job. If you hate mornings, you can schedule your classes in the afternoon and evening. If you like wrapping up early, you can choose 8 a.m. time slots.
The opportunity to mentor the future workforce might be all the gratification you need. Working with students and helping them through coursework can give you a great sense of personal satisfaction. And the longer you work, the more your students will teach you.