You can see datasets purporting to be, for instance, details about students appearing for various Indian competitive exams for as little as $50-100[1]. Other datasets are costlier, of course.

If you're marketing to that demographic (e.g. potential ads for private colleges, or other courses), your budget won't be super high, but you might well spend a little for a bunch of emails of potential leads.

[1] https://www.reddit.com/r/india/comments/63s18q/student_data_...