for instance, the TAM Brazil AirPass: 4 Destinations for US$ 479.00 (extra destination US$100)
... and you can fly from Sao Paulo to many places, including:
from São Paulo (GRU) to Rio de Janeiro 45min US$160
from São Paulo (GRU) to Igazu Falls 2,5h US$280
from São Paulo (GRU) to Fortaleza 3,5h US$456
from São Paulo (GRU) to Pantanal (Cuiaba)2h US$255
from São Paulo (GRU) to Manaus (to the Rain Forest) from US$446
from São Paulo (GRU) to Curitiba 70min US$215
from São Paulo (GRU) to Florianopolis 70min US$432
from São Paulo (GRU) to Salvador 2,5h US$330
from São Paulo (GRU) to Recife 3,5h US$ 490