Mexico has a very small, very wealthy upper class, and a huge lower class. The poncho salesmen are lower middle class. I used to deal with street vendors and the people who supply them when I was working my way through NMSU selling guitars and felt paintings. The very poor eat tortillas, beans and nopales (prickly pear cactus), cook on charcoal or kerosene. The poncho salesmen eat some sort of meat once or twice a week, and may have butane to cook on or electricity in the city. I doubt if this has changed much since the 1960's, other than the drug trade. There was not much crime in Juarez when I used to go there. I don't think I'd go there at all now. I made more on those paintings and guitars than those who made them, but I also paid more than they could get for their merchandise on the street, so I was a sort of hero, and it was impossible for me to pay for my beer after I had been in business for a month or so. Of course, I took all the risk by paying in advance for the merchandise. It was understood that I could not return anything. I did reject a painting or two that I thought would not sell and more than one guitar that had a rattle or was impossible to keep in tune.
The poorest Mexicans in Cd. Juarez were still better off than the campesinos in the rural rancherias.