I've spent a lot of time in a lot of places (including several from that list), and I'm not sure what conclusions I'd draw about cost-of-living versus much of anything.

One unusual thing is often the very high cost-of-living in some cities in low-income countries. Like, if you can pay $50/month for housing an hour out of the city, why do people who earn a fraction of what I do spend $1000+ on housing in the city? Why don't people and businesses relocate?

I'm sure there's a good reason (and probably not the same reason everywhere -- crime, schools, economic opportunity, social standing, etc.), but apparent paradoxes like that are interesting.