Well actually the schools don't give away much. They just let you take the course, but if you want credit for it then you need to pay the fee.
So instead of fighting the problem headon I was trying to suggest that maybe there might be a way to redirect the forces at work. LEts say Sue had a website called
"Magna Cum Laude graduates of the Sue School of Architectural Illustration". So if you are a registered graduate of the course your best work and your CV can be posted in a gallery receiving international attention.
So suddenly a lot of people are sneaking into her class. However, low and behold they find they learned something and they are becoming pretty good. Now they have no doubt about their skills, they would like them seen and certified to. Since they did not pay they can not been seen on Sue's architectural rendering site. So they pay for the course retroactively and now they are part of a respected gallery/showplace.
I am just suggesting there might be more to gain from channeling human nature than fighting it head on. Not sure of the validity, but am just trying to float a concept.
When I hit a brick wall I always like to back off and think about more productive approaches and study elegant solutions to similar problems.