Originally Posted by SPSTiger

Here's verbatim from an email from Dante when I inquired about transport from downtown to AEP:

...from almost anywhere downtown to AEP it takes about 15 minutes, but on rush hour (4 PM to 8 PM), allow at least an hour to get there, and you also need to be there one hour ahead of the flight time, so get a radio taxi ( your hotel could get one for you) or if you are in an apartment, call 5238 0000 Radio taxi Premium) and arrange for the transfer, the cost should be approx. 15 Pesos ( US$ 5). When you come back from Iguazu do not leave the airport building to get a cab from the street, they are not reliable, best to go to the "remise booth" inside the building and arrange a transfer, it may be a little more, but you pay right there and avoid unpleasant surprises.