The GDP numbers are not segregated by the source of taxes paid. Those GDP tax numbers include corporate taxes. Even after all of the tax breaks, the U.S. does have the highest corporate tax rate in the Western world at 35%, and most corporations are not able to avoid taxes like GE. [EDIT: inserted not]

Furthermore, though the top 1% pays a quarter of all taxes paid by individuals, the next 9% (salaries down to roughly $110k) pay 50% of taxes. In other words, 10% of the country pays 70% of the taxes! For this 10%, taxes may trump healthcare. http://www.ntu.org/tax-basics/who-pays-income-taxes.html http://www.heritage.org/budgetchartbook/top10-percent-income... http://www.american.com/archive/2007/november-december-magaz...

For everyone else, healthcare costs will defintely trump taxes.

Here's another source of data.

http://www.npr.org/blogs/money/2012/04/05/149997097/what-ame...

This shows that people spend more on each of transportation, housing, and food than they do on health care.

But how do healthcare costs scale with income?

They don't, generally, as healthcare costs are bounded but income is not. So the rich ultimately pay proportionately less for healthcare relative to their income (though on an absolute sense, they pay significantly more).