[W]ith a tax, the price is set not by the market, but by the legislators’ personal beliefs about the costs, which of course people disagree on.
Since there is no such thing as an unregulated market, there are always taxes. If we follow Nullius’ argument, the price is never set by the market, and can therefore never be as “objective” as his claim would presume preferable.
Some hands are more visible than others.
Even if we were to grant for argument’s sake the realizability of his theorical construct, his preference for this ideal over other ones will always depend upon intersubjective beliefs.
Invisible hands are still hands.