In a rare turn, the Upper East Side’s C&M Arts is selling about half of the works in “About Faces,” a show of photographic and painted portraits by a mix of contemporary stars and hard-to-get modern masters. Usually the gallery exhibits work culled from collectors and museums, with only the odd gem or two to be sold. While only two pieces have been purchased since the show’s opening last Thursday (a Warhol and an $85,000 Joseph Cornell, Bebe Marie, 1938, pictured), C&M’s co-organizer of the show, gallerist Jeffrey Fraenkel, sold several when he mounted “About Faces” in San Francisco in the fall – including a $51,000 Hiroshi Sugimoto portrait of Fidel Castro. Of course, one difference between last fall and now is the jittery economy, so sales could show just how skittish the art market has gotten. For those still feeling flush, the twenty works on offer range from a $2,200 August Sander to a $1.5 million Paul Klee.