Yay! We came in at sixth!!!
Thing is, cost of living is not a useful measure unless it is combined with median income, and standard of living indexes.
So, yes, where I live is expensive. But my wage is higher also, and I have an excellent standard of living.
This means I get to complain about my morning coffee being slightly bitter, or even travel overseas and act like an arrogant arse.
(okay, so the bottom line was a joke, but the rest of this post is accurate)
From the same site you got the cost of living information is a handy (if subjective) sortable list;
http://www.movehub.com/city-rankings
This allows you to see relative purchasing power (comparison of wage to cost of living) as well as things like average income, crime stats, etc.
Consider...if I can survive on $500 a month, and the average wage is $500 per month, then I am in the same relative situation as someone surviving on $5000 with an average wage of $5000. (ie. parity)
You also mentioned about being able to live like a king. That's also relative. It's possible that some of the people posting here DO live like kings, in relative terms.
I've lived in a poor country, and could survive there with much less money than I need in Australia, for various reasons. My ability to earn income was actually very good, as I received tax breaks, and was paid in US dollars rather than the less stable local currency. But the quality of life was extremely low in relative terms.