an average taxi ride will be about 90 minutes each way, and could total about 300 reals roundtrip.

while by bus, average travel time is about 120 minutes each way, at a roundtrip cost of about 30 reals per person, depending on the buses used.     

getting to this part of rio via public transport can be complicated for visitors who are not familiar with the city, or not fluent in portuguese - a personal guide or assistant is always a great idea.