One of the largest U.S. retail deals last quarter was the purchase of Plaza Mexico by private-equity firm Sterling Organization for nearly $165 million in a bankruptcy auction, showing the strength of bricks-and-mortar retail. Florida-based Sterling believes Plaza Mexico is well worth the purchase price and the millions it plans to spend on improvements, according to Brian Kosoy, chief executive. The real estate focused company estimates nearly 400,000 people live within 3 miles of the shopping center, most of them Hispanic.