Earlier quoted context omitted.
> I value lots of works of art very highly, but I've hardly ever considered buying art. Then either the art you admire is way out of your price range (I admire Alphonse Mucha, but I don't own any originals!), or the artists you admire are doing a poor job of letting you know that their work is affordable, and would add to your quality of life.
"The principle of revealed preference." If he's not buying it, he's not really valuing it. Like the old joke about two economists who walk past a porsche. One remarks that he'd give anything to own that car --- the other responds, "Clearly not."
An artwork is not a porsche. Even if I had anywhere near enough money to buy a Kiefer, there would be no room for it in my house, and it would not belong there anyway. I think it is valuable simply that Kiefer's paintings exist, and would be even if museum's weren't willing to pay for them.