Mama needs a brand-new bag! According to a recent study by Baghunter, the legendary Hermès Birkin bag is a better investment than both gold and stocks. The luxury site compared the returns on the three investments over a 35-year period, and, as it turns out, the value of the Birkin, which starts at $11,000 on Baghunter, has never decreased. In fact, while the values of gold and the stocks have fluctuated, the top-handle tote's value has steadily increased more than 500 percent in the last three and a half decades. That makes for an average annual increase of 14.2 percent,...