The Manuel Lion shuttle service takes you to a depot across from the Sheraton/Park Towers in central BA. They then transfer you onto a smaller mini-vehicle or taxi to take you to the IC (and your other passengers to their hotels) at no additional charge. Unless there are more than two of you, this is the most cost-effective way to get into the city. As noted they do take credit cards so you don't have to worry about local currency until you get to an ATM downtown.

For the return I do take a cab to EZE and never ha d any problems with drivers the hotel calls up...just check out and get a cab called by the door man, don't pre order or you'll get a limo type car at twice the price. Cabs are plentiful around the IC and they get reputable ones. The real rip- offs are at the airport where you should not buy any local wines or alfajores as these are over priced in US$s. (If you're looking for fine wines there is a boutique shop in the hotel for higher end offerings.)