“No living artist has ever taken so many of his or her own works directly to auction. Instead, most rely on galleries to dole out a handful of pieces at a time to curators, collectors and, eventually, the broader public. Mr. Hirst and Mr. Dunphy are betting that they can make more money by cutting out the middlemen altogether, selling new works themselves to the highest bidders. If the sale is a success, other star artists like Jeff Koons and Takashi Murakami may well follow suit.”