has taken casual to a haute new level. While volunteering Wednesday at a D.C. food bank, the First Lady sported her usual J.Crew cardigan, a pair of utilitarian capri pants and, on her feet, a sneaky splurge: trainers that go for $540. That's right: These sneakers - suede, with grosgrain ribbon laces and metallic pink toe caps - are made by French design house Lanvin, one of fashion's hottest labels. They come in denim and satin versions, and have been a brisk seller all spring.