My cost of health care is from the OECD (Organization of Economically Developed Countries), but those numbers are available in a lot of places.  The OECD has also rated health care systems and found the US last in performance, but I base my "performance" evaluation on information from the CIA World Factbook (https://www.cia.gov/library/publications/the-world-factbook/).  According to the World Factbook, only Denmark and Portugal have a lower life expectancy than the US (and Portugal spends 75% less per capita than what we spend on health care).

"and why is insurance twice as cheap in Western Europe", or more exactly, why is health care in the US twice as expensive?  Because they have figured out how to do it, and we have not   (or are not willing to do it.)  Maybe privatization is not the way to achieve an economic cost.