2. Since 1950, food prices seem to have grown at the overall rate of inflation, so food is cheaper relative to the median income. (https://research.stlouisfed.org/fred2/series/CPIUFDSL/)
3. Healthcare is usually considered essential, and its cost has increased as a fraction of median income, but I would bet 1950's medicine would be dirt cheap today if it weren't illegal to practice it: no MRIs, no patented medicines, no chemotherapy, etc. What we get in exchange for the higher cost is a decade of life expectancy.
4. Here is an interesting article I found on this topic: http://www.theatlantic.com/business/archive/2012/04/how-amer...
It's not quite clear that the extra decade of life expectancy comes from the more expensive medicine.
(I agree with the rest of your arguments for what it's worth.)
a house cost $22,000 (ie, 5.3x an annual income)
a loaf of bread cost $0.18 (ie, 0.004% of annual income)
Today, a median household income is $51,939 and
a median house costs $188,900 (ie, 3.63x an annual income)
a loaf of bread costs $2.26 (ie, 0.004% of annual income)
Current median income and house prices from Google, loaf of bread cost from http://www.numbeo.com/cost-of-living/country_result.jsp?coun....
All dollars nominal.
EDIT: Here's a fancy chart I just found, thought it might be useful to make the point:
http://www.bls.gov/opub/ted/2000/feb/wk3/art03.htm
Also I'm not sure if it's a typo, but your comparison between "average income" in 1955 and "median household income" today seems to hurt, not help your point.
As for real human needs , like healthcare - it seems to be that with technology ,at some point in time, they will be fully solved, so no need for further growth.