So how can a smart investor play the collectible game without getting sucked into the Koons hype?
Grant suggests buying historical documents: letters from Abraham Lincoln, bills signed by Thomas Jefferson and even public credit reports from Alexander Hamilton. Of course, prices for historical documents have soared along with art.
And a yellowed letter doesn't look as good over the mansion mantelpiece than a Hirst or Barnett Newman. But the names Jefferson and Lincoln may be more likely to hold up over time.
"Sell Newman, we say, and Jeff Koons, too: buy the Founding Fathers and—as far as that goes—Abraham Lincoln," Grant writes.
—By CNBC's Robert Frank. Follow him on Twitter @robtfrank.