looking for a place in BA

Hi, my name is Ema and i´m from Germany. Can someone recommend me a good and cheap place to stay in Buenos Aires? i´m looking preferably for a hostel in the area of san telmo or surroundings. i´m planning to stay 10 days in BA and then go to Bolivia and Perú, which is the best way to travel to there?
Thank you for the answers..

Travel to Bolivia/Peru: by bus. Depending on how much time you have, consider making intermediate stops. At least in Salta, but Jujuy and Tucuman are also very nice, as well as a load of smaller places in north-western Argentina.

As to accommodation: my knowledge of the Sant Telmo area is not recent, but I stayed in the hostal de San Telmo (Carlos Calvo street 600-something) on four separate occasions between 2003 and 2006. Cheap and cosy, although not very clean and comfortable. More recently, I stayed in Rancho Urbano, which I highly recommend, but that's much more expensive and in an entirely different part of town.

If I was you, I would go by bus to Cordoba (which I have very good references), then to Salta and Jujuy, and then i would go to Bolivia. I believe that it is the best option. In the north there are a lot of good places to visit. About the accommodation, in BA I stayed in the Garden House, in San Juan street, which I recommend because it is cheap and the staff is great.
Regards