Earlier quoted context omitted.
"...should be able to set price caps on artwork owned by corporations" Because copyright protection is not a right, but a limited privilege granted by the United States Constitution and intended to "promote the Progress of Science and useful Arts", not to make a sure $ for some corporation. Hence the idea of compulsory licensing, for example. If the cost of the license, though, is prohibitive, it has the same effect…
The "limit" on copyright is duration. The market owns price. You haven't answered my question.
Yes, I did. See the other comments on compulsory licensing as being state-sanctioned price limit, if my own answer was not clear enough.
Also, a reasonable counter-question is, what gives someone the right to prevent me from making a copy of a digital entity?
Intellectual "property" is quite different from physical goods, and the fact that the Constitution has a special clause for copyright suggests that IP was not meant to be equated with, say, land or other material things.
Perhaps copying is the real right, with government offering to restrict that right for a period of time so as to offer incentives to people to make their creations public.