Why is a cup so expensive in the supermarket? It's incredible. Is this a lie?

No, it's a lie, because the materials are different, the regional labor force is different, the manufacturing technology is different, and the price of each commodity varies with the circulation channels.

For example, the price difference between food-grade stainless steel and ordinary high-speed rail stainless steel will be twice as high.

On the surface, we can't see the difference between goods of the same style. Only the merchants know the quality of the materials, so you can only buy things safely, keep your eyes open and think more about food.