Because the information gap is different, people are willing to pay even if it is several times higher than the cost. This is often the case. You don't know an industry, but when you need related products of this industry, you have to pay for the behavior that you don't know this industry. For example, the cost price of a cake is 50. But the average store will probably sell it at 100 yuan, and the price higher than the cost is counted as labor cost. However, when you don't know the cost of this cake raw material, if you buy a cake, others may find that you don't know how to do it, and may quote the price of 150 yuan, which is three times higher than the cost. Because you need it, but you don't know how much this cake will cost, so the store says as much as possible. Of course, this is just an analogy, and the general merchants are still very conscientious. But it is because you don't know an industry that you get less information than others, so even if something costing 5 yuan costs 20 yuan, someone will buy it.