Can Costs be Subjective?

I was listening to a presentation yesterday for an experiment to try to uncover some of the reasons we treat intellectual property with different norms than we use with physical property. We also read an excerpt from The Economic Structure of Intellectual Property Law by William Landes and Richard Posner.

Posner and Landes raise some interesting points, though much of their stuff seems nonsensical upon further review. One claim I enjoyed was that, "Many authors derive substantial benefits from publication that are over and beyond any royalties," such as pecuniary income, prestige, etc.

One of the claims proposed by the experimenter was that intellectual property "costs a lot to create." This is supported by Posner and Landes, who claim that there is a two-tiered cost of intellectual property: the "cost of expression," for which there are no returns, and the "cost of making copies." But I'm not sure this is exactly right. For the publisher, the cost of expression can be measured in terms of dollars, but separate out the artist. For him or her, I think the cost is much more subjective, and said cost needs to be thought of as a value to be better understood (similar to the way a "wage" should be thought of as a "cost (of labor)" when plugged into an SD graph).

We see this phenomenon developing before our very eyes: software programmers collaborating to create an operating system that rivals the best operating systems available for purchase and making it available for free to all; bloggers synthesizing content and publishing original ideas for all to use; even musicians are moving towards this trend as they move away from big record companies and toward independent labels. This last movement shows that the cost of expression, for them, is probably fairly low, because they continue to produce music even as it suffers from piracy across the internet.

Posner and Landes make one other interesting claim: that close examination of historical authors, such as Shakespeare, show that much of their work was borrowed almost exactly from their predecessors. Shakespeare wrote in the age before copyright laws, and perhaps this allowed him to be creative in ways we cannot today, as we are restricted by risk of plagiarism or violating copyrights. All the new mediums of expression (see Tyler Cowen's fascinating Create Your Own Economy) are growing rapidly, and if copyright laws cannot keep up perhaps we will be allowed to borrow more from others and we will see creativity manifesting itself in new ways.

Am I the only one who believes costs can be subjective, or is this a new way to look at intellectual property in the modern world?