Since the government limits how many dollars anyone in Argentina may obtain, an informal, parallel or black market (informal, paralelo o mercado negro) exists where people may also exchange pesos for dollars. People are willing to offer more pesos for each dollar in the informal market than is required to obtain dollars in the formal market. This informal exchange rate is known as the Argentine blue rate or the dólar blue (never referred to as the dólar azul).
The blue rate represents a more reasonable value of the Argentine peso compared to other currencies than the official rate quoted by the government. To exchange dollars for the blue rate, a person must know or find an illegal money changer, known as an
"arbolito financiero". The location of an
arbolito is known as a
cueva.
Essentially, the problem here is that you will not be able to re-export the pesos you have bought with the BTC, well I think from memory you get a limit or something really small.
So you will have to spend it all there, but as others mentioned in this thread, do the selling there.
Here is a blog that will give some info on where the sellers are, and what black market USD conversion rates of the day.
http://www.dolarblue.net/
