3.1.3.1 (Exercise) Have prices actually risen? Economists generally agree that the meaning of “prices have risen” is that you would prefer past prices to current prices. What makes this challenging is that the set of available products change over time. Cars have gone up significantly in price, but are also more reliable. Would you be better off with your current income in 1913 than today? You would be very rich with current average income in 1913, but not have access to modern medicine, television, electronics, refrigeration, highways, and many other technologies. If you made $40,000 annually in 1913, how would you live and what would you buy? (Do some research.)
-- R. Preston McAfee, Introduction to Economic Analysis
A 100 page comic book cost me $0.25 US in 1970 or so, it is a few US$ now. A 12 oz soft drink cold in a deli was about $0.10, it is more usually $1.00 now. A gallon of gasoline $0.29, now about $4.50. Not a single one of these is of notably better quality now than it was then, I'd say they are directly comparable and are quite different enough in nominal price so that there can be no doubt.
Sorry not to go all the way back to 1913, but I was 13 years old in 1970 so it was easier to use what I could remember.
Rationality quotes time!
The usual rules: