Pay-what-you-can classes allow each student to pay the amount he wants for the class, instead of requiring a set amount. Schools often consider the amount paid for these classes to be donations. Some schools recommend a certain donation amount or donation range, and some require a minimum donation amount.
Pay-what-you-can classes are common at schools that offer one-time classes, such as yoga or dance schools. These schools often have some pay-what-you-can classes along with other fee-based or members-only classes. Students with a membership can typically attend pay-what-you-can classes at no additional charge and without a donation. Some schools only accept cash donations, and some leave a donation box out for these types of classes, allowing students to donate anonymously.
Pay-what-you-can classes allow all students to attend, even if they can't afford classes or a membership. These classes also allow other students to charitably donate a larger amount, if they want.
In general, colleges and universities don't offer pay-what-you-can classes, instead charging a set amount for each unit a student takes or a set amount per semester. At schools that charge a set amount per semester, students can save money by taking a higher number of units. Other ways students save money is through scholarships and financial aid.