Fashion moves so fast these days it is hard to buy a backup of any of your favorite clothing or accessories before the season is over and the designer pulls it from the store. Thankfully certain brands, such as M.M. Lafleur, ATM and Rag & Bone, repeat some of our favorite client picks season after season, but most do not. I recently did a Google search for “Nike Siren Snakeskin Sneakers,” and hit the jackpot on Poshmark for my favorite but quickly disintegrating sneakers. A client and I were lamenting the passing of the Alberta Ferretti di Philosophy store we …