Virginia Postrel marveled at being able to purchase a bag of flour for 69 cents. Brad DeLong agreed, pointing out that a bag of flour has about 7500 calories.
Consider the overwhelming bulk of our ancestors half a millennium ago--Eurasian peasants circa 1500. Something like three-quarters of the value of what they and their villages produced was foodstuffs. And close to the Malthusian edge as they were, they were lucky if the foodstuffs they produced got them 1900 calories a day.
In other words, Postrel purchased four days worth of pre-Industrial output for 69 cents.
Discussion Question. What are some of the adverse consequences of the tremendous productivity of modern agriculture?