I am traveling to Argentina in November and looking to buy two one-way tickets (FTE-USH and USH-AEP). Searching for fares on the Aerolineas website returns surprisingly low fares given my understanding of the two-tier pricing system (US$101 for the first and US$140 for the second). The terms and conditions appear very vague on many things, such as whether or not additional charges will apply to tickets not purchased in Argentina and how/when these are to be collected.

Can anyone offer advice on this? I understand how the two-tier pricing used to work (I made a SA trip a year ago and was looking at BA to Calafate, when the R/T fares were US$800), and have heard something since planning this trip that the recent nationalization of AA meant heavier subsidies to southern flights and maybe suspension of the two-tier fare policy. These fares seem too good to be true, but I am not trying to game the system through the AA website-- I am using the US as my country of residence, preferring to know what my real cost will be up front.