To live in BsAs on a basic level cost me about 700 pesos a month but that doesn't include "entertainment", which will boost it up to 1000 a month.
This was by living at a Hostel paying a monthly rate, cooking my own food, washing my own clothes and using public transit. It was a nice place with internet, TV and all of that included. A great way to meet other travelers and I would also live in different parts of the city for a month at a time.
Living outside of BsAs isn't that much cheaper, which was a surprise. It's actually more expensive in the south of Argentina or especially, in heavy tourist areas.
If I'm travelling within Argentina, then my monthly spending is at least double.