To all of you interested in this topic, I am very surprised. I just came back from a trip to Argentina and Chile. The Chilean consulate in Chicago confirmed this charge of $100 before I departed in January. However, I did not fly to Santiago. I crossed the border by bus, coming from Mendoza. The 3 of us americans, HAD THE $100 DOLLARS BILL FOLDED IN OUR PASSPORTS, but they did not request any entrance and/or visa fee from us.
We were waiting for such charge at the airport in our way out. The same. Nothing was said. In fact I had been told that everyone had to pay an airport fee of about $20. We did not. It is included in your airticket cost? - I had 2 free tickets and all I paid American Airlines was $10 dollars, when they issued my e-mail ticket several monthas ago!
I would like to hear more opinions about this matter