Most markets have also had a wide variety of regulations. It seems perfectly reasonable to me that large retail operations would be prohibited from attempting a predatory scheme depending on individualized pricing. There's a tangible difference between one off purchase contracts and selling into the consumer market at large.

Sure, haggling was historically the standard but that just isn't the way these modern operations work. If an outdated practice gets caught in the crossfire when protecting consumers from imminent harm I'm okay with that.