Tiendas Chinos are the Neighborhood Markets that seem to dot the residential streets in BsAs. Yes, the name many not be politically correct in other parts of the World, but that the go to name in BsAs. Some have very well thought out Wine Selections, while others may have older inventory plagued with dust (but those are the minority from my experience) They are open late, have wonderful selections for the most part and they are a great place to find wine! And. according to this article the least expensive place as well. Read on and Happy Drinking!
http://www.areadelvino.com/articulo.php?num=29593