OH- he means Airport Tax.
No, they include it in the ticket price now. Which is much nicer than having to wait in line.
Airport taxes are far from unique to Argentina- its just that in most places, like the USA, they have been included in the ticket price for a long time.
The US sometimes calls it a "International Departure Tax", and everytime you fly out of the USA, you pay it.
Its $15.40 now, I believe.
http://www.airlines.org/economics/taxes/IntlDepartureArrivalTaxes.htm
They just hide it better in the US, but you are paying it.
I have been in a variety of other countries over the years that did it the old way, though- that made you pay at the exit gate before boarding the plane.
I believe that Peru and Venezuela still do this, for example, and Thailand did it for a long time.
Here is a list of various places- not sure how current it is, but it says Greece is 12 euros, and Ghana is $50 US, for example.
http://www.amerispan.com/travel/article/Don_t_Forget_about_Departure_Tax_when_Studying_Abroad_/241