From another angle, why would the customer spend their time (which has value to them) in a transaction where they don't get any?

> From another angle, why would the customer spend their time (which has value to them) in a transaction where they don't get any?

Well I for one always took issue with the rational consumer model. It is possible that people trade things they value for things they don't, because people do not always act rationally.

That’s a larger discussion but much of the economics of it gets cancelled out with the notion of “revealed preferences”. Economics doesn’t really account for whether an individual consumer is rational for buying junk food, scratch tickets, and liquor; it just sort of observes that you behave as though you want those things and models from there. The internal struggle of will between the “you” who binges on Oreos and store brand vodka and the “you” who wakes up on New Years morning with a hangover and a sincere desire to turn your life around isn’t necessarily within the scope of economics (unless the New Years Day “you” promptly purchases a gym membership that you never show up for!)

But we're talking about basic stuff here like buying bread...

Have you seen the variety of bread available, and the price range thereof? If all of it is purchased on rational valuation grounds, I think we must end up with a fairly loose definition of "value"

I'm sorry, but you still seem to be missing the point ? This isn't about bread varieties either, I would assume that most bread is bought within an order of magnitude of prices.

What's the difference between buying flour etc. to bake a cake to sell, and buying food to eat, so I can continue to function and sell my labour?