Those who do transcendental meditation?

Why is everybody keeping quiet about this? Selling enlightenment for a $2000 fee is rodiculouss. The teachings weren't even created by the one who trademarked them. Id like for somebody to at the very least elaborate on this form of meditation. I understand that a mantra is used. I've been told that you sit there while chanting a mantra in your head for at least 20 minutes. What's supposed to happen in your mind when you do that??