Minimum wage in 1975 was around 2 dollars and many rentals are two rooms or more. Grocery store may have averaged higher as most included meat cutters on prepared products and I bet that includes management. The shelve stocker likely getting 2 dollars an hour.
Ya let us value that the same as a guy working in a mine or someone developing software. Get serious people. We are paying to subsidize someone to work at Walmart is because we choose to do this. And why wouldn’t a person want to work a higher value job if the government is willing to top them up to a higher rate?