I was listening to The Michael Shermer Show where he was interviewing Marian Tupy and Gale Pooley on their new book Superabundance.
A statement made by one of the authors hit me. We buy things with money, but we pay for them with time. They went on to discuss how economics made a mistake by measuring prices in terms of monetary cost instead of measuring the cost of goods/services in work-hours.
One of the dramatic examples is how much in terms of time we have to pay for an hour of light.