The difference between a $0.8 meal and a $15 meal is not that the latter is (say) 10 times as nutritive as the former. It probably is 2 times (at most) more varied than the former, containing a richer set of rare compounds like vitamins and other stuff, but the energy level is hardly any bigger. The real difference between those, and say between any of them and a $600 meal, is that the gal eating the most expensive would be 750 (600/0.8) times as likely to receive food if there were not enough food for everyone.
If, say, we went into war and had to ration food, with long long lines to get a dirty cold plate of soup, those 3 guys would all get the same plate of food, but the $600-meal guy would now be the first in line, the $15 guy somewhere around 40th and the $0.8 guy 750th, or as close to the end of the line as it gets. (All those figures are meant as proportions, right?)
It is very easy to see money as having a concrete value, to believe that it has one fixed and simple quantity and that’s all. But actually money is relative. 600$ for a meal is too much only because $15 is reasonable. At other circumstances 600$ might be too few, or 80 cents too much. Money only makes sense in a system-scale. The value of money lies not in money itself, but in the socio-cultural feedback loops around it.
To the point that a $10 cheese-burger is not twice a $5 burger.
The price is just another pissing contest. Useful, and necessary, but petty none the less.