Brazil in the past couple of years has had a surge in LCC type carriers, TAM is considered a full service carrier so I they would be on the pricey end of the scale..
Some lCC's in Brazil include - Gol (as menitoned above), Azul (founded by the B6 founder), webjet, TRIP, etc etc Some of these websites might be in Portugues only.
Full Service
- TAM
- Avianca Brazil, Im sure there is more, but I believe Varig and GOL merged their operations.
Brazil as you mentioned is a large country so they do have a host of airlines. My airline only has ID 90 agreements with TAM and GOL so apparently ZED agreemends are not common in Brazil.

Regards,

Chepos