Since the New York and European media have outed Montauk as the “it” place to be, several new stores have opened and others are raising their visibility. One of those is Melet Mercantile. Owned by Bob Melet, it’s in a rambling warehouse on Shore Road. Although it is now entering its fourth year, not too many people knew about the shop — until now — and that’s only because Mr. Melet finally allowed an interview.