Some tips for the Amazonas. As I mentioned flights from Rio;Sao Paulo to Manau is 800USD return. Pretty expensive. Some tips:
1. Coming from another country, fly straight to Manaus. Then youonly need a one way flight out of the city to another brazilian city. From there you can travel by buses to the other cites.
2. You can prebook a forrest hotel which is either 4 or 5 stars. They are very nice but incredibly expensive. Can be around 150-200USD a night a person. ouch.
3. For those on a budget, youcan land in Manaus and youcan do a jungle adventure for 4-5 nights. You get the same experiences in that you see the jungle, swim with pink dolphins, boat thru the river negro, pirana fishing... but here you don´t sleep in a 5 star hotel each night. Youwill sleep in a hamock on the road before heading to the next destination. The trip is rustic and really jungle. Don´t allow them to con you into more than 100 reals a night per person. I have heard of as low as 75 real a night while for the same tour a friend paid 250 real a night. So bargin bargin bargin
4. 5 days is really enough unless you are a jungle person. It is even straining. So I have been told.
5. You can boat thru the river negro and to some parts with some kind of cruise ship. This is just as expensive as the 5 star hotel.
6. Bus to Manaus city is around 50 hours thru rough tough sort of raods. Not recommended. However possible but dangerous.