I have noticed, in many cases, that Argentinos seem to want to do the opposite of what a free market would nomally have them do when business falls off. I.e., they tend to raise prices to get more money from fewer customers instead of lowering prices in order to attract more people to their business.
I don't know that I would look at prices falling, at least for tourists, any time soon. Most people own their apartments outright - mortgages are difficult to impossible to get here so they are not usually trying to ensure that they have enough income from the apartment to offset their mortgage payment and can therefore ask the higher price than one would normally think.
Prices in long term rentals seem to have stabilized and maybe even dropped a little. I've been looking for an apartment in town and have been surprised at some of the deals that I've come across.
But those long-term rentals are not priced for foreigners who are renting temporary apartments. They are two different markets and you are talking about the market that will always try to attract the higher-paying crowd. When there are no more tourists who are willing to pay the prices, the prices will fall, after awhile.
BTW - a furnished apartment for $800 USD a month, even if it's a studio, is only $27 USD a day. Much, much cheaper than hotels. Even at $1200 USD for a one bedroom apartment, you are still looking at $40 a day, and I don't think there are any hotels here in Buenos Aires that are worth staying in for the same price, compared to how nice a big a one bedroom apartment is to a little hotel room in one of the cheapest hotels in the city.
I guess what I'm saying - it's all relative...