First, you should call DebtorCC and see if you qualify for a fee waiver: 1 (800) 610-3920. You can also follow the steps outlined in this article on how to apply for a fee waiver for the course.
If you're not eligible for a fee waiver, please do your best to save up or ask your friends/family for the money. A few people drop out after making it through the questionnaire because they can't find the $15. Don't let this be you.