It seems like only a few days ago that Cedric the Entertainer was celebrating opening night of his Broadway deut in the revival of David Mamet's American Buffalo, which co-stars John Leguizamo and an all-growns-up Haley Joel Osment. But not enough people want to see the trio do Mamet's dialogue justice. Previews began only on Oct. 31, but by Wednesday, the producers had posted a conditional notice closing the show Sunday, Nov. 23…unless ticket sales improve. You can even get a second ticket for a nickel (get it? buffalo nickel?)?! So go on, pay it forward, so to speak.