I'm pretty sure you don't have to have proof of return flight. someone correct me if I'm wrong (because that's something i really need to know before I move there in August!)... but as far as I've read, you just have to purchase the 3 month online before you get there and then you can renew that...
Decided I wanted to change up my life a bit and move to Buenos Aires. I've never been there and I don't speak much Spanish... so it'll certainly be an experience. I'd love to meet a young group of people that have available housing in a great location. (Have been doing research, possibly Palermo...