Does anybody know if there are cheap ways (buses or trains) that go from the North of Argentina, or Buenos Aires to the North Of Chile (San Pedro de Atacama or nearby)? Any advice would be very welcome, thank you very much in advance!
If I am correct, there still are buses from Salta to San Pedro which take about 12-14 hours
If you are looking for cheap then you might want to reconsider San Pedro de Atacama. It´s not exactly what one might call cheap there. One of the most expensive places in SA to be more precise.
If you are looking to do a trail to Uyuni on the salt flats from there you might be better going from Tupiza just into Bolivia. Very pretty and cheaper. Also easy to get to.