Typically, your trip will involve two parts: the first between you home institute and Buenos Aires, the second between Buenos Aires and Bariloche. There are two cases:
The round trip Buenos Aires - Bariloche can then be obtained separately for a price of approx. $300 but tickets at $200 can be found if booked sufficently in advance.
Of course, Bariloche can be reached by plane form Buenos Aires. The companies operating this route are Aerolíneas Argentinas, Austral (actually, a subsidiary of Aeorolíneas Argentinas), LAPA (a partner member of United Airlines/Star Alliance frequent flyer program), and some others with smaller planes. As we already said, the typical price for a round trip is $300, but tickets at $200 can be found booking in advance.