Madonna can’t wear a Britney Spears T-shirt all the time, so Dolce & Gabbana’s sexy little tops were just right for the Grammys last week. After their brilliant pictorial Madonna T-shirts for spring, Domenico Dolce and Stefano Gabbana went subtler, relatively speaking, for early fall, with tanks and T-shirts appliqued with “Material Girl.” The designers started showing the collection to retailers three weeks ago, and sent a little package off to their favorite muse. She obviously loved the idea, wearing the black tank with blue lettering for her performance and the white-with-red T-shirt for the rest of the evening. The next morning, the phones at the showroom starting ringing off the hook with calls from retailers who wanted to increase their orders, or get in on the action. All so that come August, material girls everywhere can share the look that comes Swarovski-studded for $1,020, or plain, for a mere $610.