Is REALLY hard to find an apartment in Buenos Aires

Not everybody is like that. Although you might be speaking of the guarantee. That's because you do not have anyone providing an apartment on the same city as a guarantee of the apartment you are about to rent. If that's the case, it is a security measure for the owner of the apartment. My friend who is also argentinian had to pay 6 months too, that's the same for us all.

Real estate in Argentina is realy good. Try it.