Cheap Chinese Cars Are Taking over Roads from Brazil to South Africa

cost can be simple, as in "how much to buy one" or complex as in "what is the wider societal cost of increased use of EVs in these kinds of economies.

It isn't clear which one you mean. I might argue that whatever the wider cost is, it may well be better overall than diesel. Or not: EV are heavy. there might be increased socialised losses in road maintenance and loss of income from fuel taxes and registration. It's complicated.