This is actually the most talked about and visited post on this board.
Click the link above for an 11 page dialogue on the topic.
It applies to any non resident, so if you are Peruvian or here with a Carnet, you pay what they call a base fare, and if you are here on a tourist visa, you pay a base plus fare that can be as much as 300% higher.
If somehow you purchase a base fare without having a carnet or DNI, and they bother to check it at the airport, they can fine you up to $178.50 per flight. Some say that means per segment, other suggest it means each way. In other words, a non-stop round trip flight could suffer a penalty of $357.00 USD.
There are currently 3 (that I know of) discrimination complaints working their way through Indecopi for what some people have declared a racist or unfair airline fee.
It has been compared to the Floridian Discount for Disneyland or the duel price system for Machu Picchu, however those comparisons, in my opinion, are patently false because those discounts are connected to other matters. Disneyland, for example, gave Floridians and especially Orlandians a discount in exchange for a tax break on the property taxes. Machu Picchu is also a tax issue where Peruvian tax dollars are used to promote and upkeep the property and it is a matter of national patrimony. Those price breaks are both based, at least in part, to taxation issues.
The Lan fee is simply a profit motivator for the airline and the funds go directly to the Parent Company, Lan Chile.
Star Peru, Peruvian Airlines, LC Busre and Taca all fly to a growing number of destinations and so far have avoided the duel price system.
Few have found a problem with Peruvians being offered a discount to promote travel and toursism within the country, but that is not really what Lan is doing. A discount would be a discount on a base fare, instead they are adding a surcharge based on nationality. They might have avoided much of the controversy if they had simply offered a discount with a DNI or Carnet number from the base fare.
This has been in news papers, radio talk shows and on CNN and a simple google search will show hundreds of discussions about it on various travel sites around the world. While a few people do not have a problem with it, the vast majority find it an unfair business practice and a hidden fee.
On one radio show, Travel Writer and consumer advocate, Chris Elliott mentioned that the only other airline he knew that had a similar practice apart from Lan was Soviet era Aeroflat.
I have contacted Lan and expressed my feelings and no longer fly them even though I do have a carnet.