It seems the rich are just now getting the info. that most of us have understood for years: shopping at Costco (or Sam's Club because they're really very similar, though Costco cakes are the absolute best and if you haven't had one, go put in an order and get the chocolate mousse as the filling) is a good thing. They save you money because you buy in bulk.
But there are still some people in the world who are afraid of what others would think of them, going to such a place. From the NYT:
One Washington hostess who loves Costco didn’t want people to know that her husband likes to hang out in the food court munching the quarter-pound hot dogs ($1.50 with a soda).
Read the article for yourself and have a laugh because you've been in the know much longer than the so-called elite.