If you want to find a college student, it is only twenty or thirty, and it is not expensive to find a graduate student. Find a teacher with teaching experience. According to NEAT8, a class is generally 1vs 1. You can find a teacher around 200, and an associate professor around 400. Professor level, you ask others, others ask you to take classes, and you don't give them 600+.

In short, the higher the level, the more money you spend.