Cheapest way to get a Student Visa? (São Paulo)

Short version: Could anyone tell me what is the cheapest way to get a student visa in Sao Paulo?

Long version: I've searched through the forums and I've seen many people mention Mackenzie and PUC-SP concerning Portuguese for foreigners classes. I'm considering enrolling in a Portuguese for foreigners class, but not so that I can learn Portuguese, rather so that I have a student visa to allow me to legally live in Brazil. (I can learn Portuguese without attending a class, but I can't get a visa without a class). Since I am effectively buying a visa, I am not concerned with the quality of the class, but rather with the price. Could anyone tell me what is the cheapest way to get a student visa in Sao Paulo?