From one of the online taxi fare calculators:
BRL $ 27 - Sao Paulo Taxi fare from congonhas to avenida paulista
Total Distance = 9.04 Km
Estimated Travel Time = 13 minutes
BRL $ 27 Taxi fare
BRL $ 33 Night Taxi fare
BRL $ 33 Special Taxi fare
BRL $ 42 Night Special Taxi fare
BRL $ 40 Luxury Taxi fare
BRL $ 50 Night Luxury Taxi fare
BRL $ 31 Radio Taxi fare
BRL $ 38 Night Radio Taxi fare
My experience has been that I have four times caught public transport with luggage from the airport to downtown in Barcelona and on 3 occasions had my pocket picked or attempted to be picked .
I have caught the 875A with luggage a dozen times and probably another 50 times without luggage (it passes by the Holiday Inn Express where I often stay) I have also caught the Metro and other buses in Sao Paulo with luggage more than a dozen times and I have not once in Sao Paulo had my pocket picked that I am aware of.
I would think twice about using Public transport with luggage in major European cities but would not hesitate to use a single service transfer in any major city in Brazil if I planned my trip in advance and was confident about where I wanted to alight.
The Airport Bus Service from CGH to GRU does not set down anywhere along the way.
Late at night in a strange city with a price difference of only $US12 , a taxi is not an extravagence but I know many backpackers who would think differently - including myself in the not too distant past.