The cost of living depends on the human being, wherever the person is even able to adjust to his daily needs. There are several surveys that prove everyone has their own style and living expenses, the economic needs of a person is different there is always a way to add income and for example are cryptocurrencies that can facilitate the need for a simple living expenses. When you earn well, you live well.
I don't agree with you on this. Cost of living is not based on an individual life style and the way they spend money. They are provisions made for the people whether they use them or not, they are there. They are usually provided by the government to satisfy human wants in that environment or country. Thus, they include social amenities, housing, food etc.
Yes. Moreover, individual lifestyle will not foot the bills and if the bills are huge, one way or the other, you will still have to pay them.
If some of these things are provided for or subsidized, it always help a lot in how people live and that totally is different from being wasteful which some people may be anyway. As long as you can balance your income with how you live, it is all good, but the important thing is that you are at least enjoying yourself in the way you can which I am sure some countries will never give such benefits.