Teri Horton, who lives in a mobile home and gets by on Social Security, isn’t exactly your typical high-end art collector. But ever since she was told that the painting she bought for $5 at a thrift store might just be an Jackson Pollock, Horton has given over her life to a tireless quest to prove the painting’s authenticity. How driven is she? Well, she recently turned down a $9 million offer for the work.