The fare will be $2.50 on Friday and I agree that it will probably rise again within months.
As for the comparison to the US or Europe, do I have to explain that few people in Argentina earn North American or European salaries? I can't understands why some expats don't get this. Please try to look at Argentina from the perspective of Argentines who do not receive income from outside the country.
My point is that the increase in a service used by almost everyone is going to cause more inflation. The maid, for example, who earns $20 pesos or less an hour will be impacted. Surely this is going to be passed on to everyone else in the form of more inflation.
Comparing fares to those of cities in the US or UK is irrelevant because it is comparing apples and oranges, however just for the record, the base fare in North American cities is seldom what locals pay. For example, in New York City the fare can be as low as $1.45 dollars (There are passes for unlimited rides). In Philadelphia, second largest city on the East Coast, the fare is $1.55 if you buy tokens. Again, there are passes for unlimited rides. Senior citizens travel free at all times (that's a lot cheaper than BA!). In London Oyster cards greatly reduce fares. I remember that buying a strip of tickets in Paris was cheaper than paying each time. There is also a major difference in the quality of transport -- all trains in the US, for example, are air conditioned, even the subway. Buses are always air conditioned, do not pollute as they do in BA as well. In the US virtually every family has at least one car. Public transit, outside of New York City, is not as universal a necessity as it is in BA - this fact makes the massive increase in transport fares a lot for the BA economy to absorb.