Kelly Crow offers an interesting theory on what might be driving this May’s market.

Never underestimate the appeal of a potential upgrade. Collectors who started buying contemporary art from galleries over the past decade have by now amassed a trove of recent examples by their favorite living artists. But now, collectors are realizing there is often greater historical (and resale) value in their artists’ earlier, breakthrough pieces, and auction houses are jumping at the chance to capitalize on the deepening interest. Sotheby’s specialist Alex Rotter said this “stretching back” phenomenon could benefit early-era Richter but also Jeff Koons, whose quartet of encased vacuum cleaners from 1981-1986, “The New Hoover Celebrity IV,” is coming up for sale May 14 with an estimate of $10 million to $15 million. The seller paid $137,500 for it in 1991.

$1 Billion in Art Heading to Auction (Wall Street Journal)