UPDATE 2: As of March 24, 2016, the reciprocity fee is no longer required for US passport holders. Canadians and Australians still must pay.
UPDATE : The Argentina entrance fee must be paid in advance as of December 28, 2012 for arrivals at Ezeiza and as of October 31, 2012 for arrivals at Aeroparque.
As of April 13, 2012, the United States has increased the price of the visa application fee from $140 to $160.
Since the Argentina entrance fee is a reciprocal fee to what the US charges Argentine citizens, it also increased by $20 to U$S 160 as of this date. This fee applies to any American citizens entering the country through Ezeiza airport. It is a one-time fee that is valid for 10 years.
No word yet on whether this new fee, which first went into effect on December 20, 2009, has affected tourism to the country or not. Considering that a family of four would pay an additional $640 for their vacation, I would have to imagine that it has caused some people to rethink their travel plans. I’ve also heard that some people are flying into Montevideo, Uruguay, and then taking a ferry to Buenos Aires, where the fee is not applied at the port.