It was Andy "Warhol's night" at yesterday's contemporary art auction at Sotheby's. One of his first silk-screen paintings, "200 One Dollar Bills" yielded a surprising $43.7 million: While the bidding started at $6 million, the price jumped rapidly between five bidders, all of whom were eager to nab the Warhol classic. The estimated price was $12 million, so it was a shock that the painting brought in more than three times that. Sotheby's refused to reveal the identity of the buyer, but one unsuccessful bidder told the Times, "I think the painting was worth it. It was rare and great. And the appealing estimate helped encourage bidding."