As Jay Gatsby’s world crumbles around him, he tells his lone friend Nick Carraway, “I’ve murdered pieces of myself to stand on this marble.” Stand on this marble. Drive a Rolls Royce. Throw lavish, absurd parties in a lavish, absurd mansion to court wealthy socialite Daisy Buchanan. Like its source, F. Scott Fitzgerald 1925 novel “The Great Gatsby,” American Repertory Theater’s “Gatsby” is obsessed with money: Who has it, who doesn’t, how do th…