It's true that rents in Buenos Aires, Capital Federal are high in comparison to average workers' salaries. However the same holds true in every major metropolitan city. In my hometown of New York City, a 1 bedroom apartment rents for around $4,000 USD per month. Do you think your average civil servant, retail worker, even entry level professional can pay that rent? Not at all, that is why SO many people live in the surrounding outer suburbs, which are somewhat less expensive, but really not by all that much. Or people double and triple up, rent rooms, etc. Or, they pay those high rents and eat eggs and rice every night, or get family help, etc. I've lived here for 7 years and rents are just as high as you see them on line, sometimes people do get slightly lower rents, but only if they know someone, family friend, etc, but again this is very rare.
If you rent via a real estate agency, you will pay 2 months commission, legal fees, etc. Renters here pay the rent, plus maintenance (expensas) which can be quite high, all depends on how large the building is and what services it includes such as a pool, gym, etc. The highest expensas are paid in those buildings with few units (15-25) as there are fewer occupants to divide all of the building expenses between, and trust me, there are many. Also, if you do get a long term contract, MAKE SURE that it states the renter is ONLY responsible to pay the "expensas comunes" which are the recurring monthly expenses, such as lighting in the common areas, building personnel salaries, cleaning supplies, administration costs, etc. and that the OWNER is responsible to pay "expensas extraordinarias" such as painting of the facades, common areas, elevator replacement and any other major one time costs. If you don't - you will end up paying REALLY high monthly costs when the building has to make major repairs. Also, in Captial Federal, the RENTER pays the real estate taxes (called ABL). So that being said, if you live in a nice building with good amenities, between expensas and real estate taxes, those charges can EASILY end up costing between 30 - 50% IN ADDITION TO the monthy rent and of course, your utility costs.
Are you aware that you also need a "garantía" (guarantor that owns a property and will sign it over as a guarantee of you paying the rent AND proof established permanent employment) to get a long term rental contract?
Sure, if you are willing to pay rent in USD or EUR that is a great advantage for the landlord, but not for you unless you have very easy access to dollars every month. They will probably give you what seems to be a "better" deal which won't end up being better for you because with inflation and devaluation, the landlord will come out ahead as by you paying them a set amount in USD every month, you are doing them the favor of "indexing" the contract against the USD in terms of inflation, devaluation and all of the other economic ups and downs of Argentina.
To summarize, renting long term is NOT very easy here, and there are few if any shortcuts that allow you to save money in the process, unless you have family members or good friends that own properties and are willing to give you a break on rent and the strict requirements that most landlords ask for.