For your internal flights, we suggest you buy a Brazil Air Pass. The Brazil Air Pass is a lump-sum airfare which enables you to visit up to 10 Brazilian cities. It is only sold outside Brazil, to foreigners or Brazilians residing outside South America and holding an international return ticket. It is valid for 21 days from the date you use the first flight coupon and you have to reserve the dates of your flights before leaving for Brazil. For further information about Brazil Air Passes and for online buying, go on BROL.