I may be dumb, but why not try to charge for the courses upfront? You offer a preview for free and charge a small fee for the full course(15$ for example). Once

I may be dumb, but why not try to charge for the courses upfront? You offer a preview for free and charge a small fee for the full course(15$ for example). Once the videos are recorded, the costs for coursera and the professor should be very low, and the number attendees of every class are in the thousands. Couldn't be profitable that way? If 15$ is still too much for some(someone who already has access to a decent computer and broadband internet), they could create a system of grants. Most people wouldn't lie just for saving such a small quantity.