Hello I'm going to travel to México DF soon and I would like to comment if You know places where to get new or expired photographic film.
i am also interested in the data of museums or places related to analog photography
Film is typically more expensive in Mexico than in the states, but I see you're coming from Argentina so I'm not sure what the options are there. I almost always buy film at Camera 1 on Articulo 123 in the centro historico. They don't have the best selection but they have Fuji Acros 100 for cheaper than the US, it's also always fresh and refrigerated.
If you walk around on Calle Donceles at Palma there are tons of photo stores with varying selections.