Controversy is good for art, but it may be better for the price of art. There's a web site with the funny name of Expresso Beans that tracks the cost of art. Run by volunteers, the site is focused primarily on graphic art and allows one to quickly and easily see how costs fluctuate over time. Or, if you're buying or selling, what a fair price might be for the work.
Take the famous (or infamous) Shepard Fairey/AP HOPE poster. A signed offset print originally sold for $30. Over the last six months, the same poster has been selling for an average price of almost $3,000; a thousand percent return!. That figure is based on 323 transactions from a print run of 600 so many of the 600 have been sold at least once. Looking at the chart, one can see several bumps: a small one when Obama received the Democratic nomination, a larger one when he won the general election, and another bump near the inaguration now sustained by the AP copyright infringement case.
My guess is that the ultimate price of the print is directly related to the size of the settlement.