This seems like a great marketing technique for up starts trying to compete in the quality/price space. In the chicken soup example, for instance, cost to produce is a strong indicator that the soup has quality ingredients, and isn't just a big markup on some generic condensed soup.

It's a similar thing with the backpack, but in the other direction - this price isn't low because we cheaped out on manufacturing and materials, it's cheaper than J. Crew because they spend too much on marketing.

The line item cost breakdown is an indicator of honesty and product quality, which of course increase trust. That's not going to work if you're selling $10 shirts for $120