I'm sure you will find useful information in this thread:
Job Offer in Buenos Aires (especially regarding cost of living in BA). Look at the advice this recent college graduate was given about living on $4150 pesos a month. At that pay level he would not be able to live alone in even the smallest studio apartment and have a decent life in BA.
If a foreign company isn't willing to pay a foreigner more than a local (two or three times the figures other members have posted in this thread) they are not worthy of serious consideration.
Good luck!