Manolo says, here is the Manolo’s latest column for the Express of the Washington Post. Dear Manolo, I’ve been invited to spend Memorial Day Weekend with my boyfriend’s family in the Hamptons. The trouble is, I’m a poor working girl. Can you please recommend some summery flat sandals that will look good enough to impress these people without bankrupting me? Molly Manolo says, as always, the Manolo suggests saving your monies and buying the most super fantastic shoes one can afford, for such purchases will give the most satisfaction over the long term, in comfort, beauty, and admiration from those…