I think that setting a price on something is best considered as a form of speech, even if it isn't exactly the same thing. A price is a statement of the value you believe that a thing has. As a free speech advocate I believe people should be able to express such value judgments freely with few constraints.

A price signal is similar to other signals we can make with speech, in that it has the potential to change behavior for good or bad. There have certainly been many bad signals via ordinary opinion that have caused harm. But most of us believe that the net benefits are such that bad speech should rarely be suppressed. I think that the same is true of bad price signals.

It isn't that well crafted laws cannot differentiate between good and bad speech or good and bad prices. They can. It's that such laws are the exception rather than the rule. So it's better policy to decentralize such decisions, so that bad ones can't be made for everyone.