[s1artibartfast]

It matters even in a Consolidated Market. The cost of a thousand calories of steak is different than the cost of a thousand calories of dried beans.

Just because the cost of dry beans has gone up 10% doesn't mean that you can't save money by eating them instead of beef.

If customers don't switch to beans despite high prices for steak, it tells you something about the demand for beef relative to the cost sensitivity of customers.

[danaris]

Ah, yes: because people who have limited disposable income were making up most of their calories with steaks...and because everyone who was buying steaks will be going aaaaalll the way to replacing them with dried beans.

Rather than people with limited disposable income already buying cheaper foods, and when those get more expensive, just having to buy less.

And, once again, for many, many things, the company that sells the steaks is owned by the same conglomerate as the company that sells the beans, and they're raising the prices in lockstep.