Crested Butte resident Roger Kahn’s first book, “How Crested Butte Became a Tourist Town: Drugs, Sex, Sports, Arts, and Social Conflict,” was a local best seller a few years ago. His latest book is a sequel of sorts, exploring what’s happened in Crested Butte and other beautiful, small communities in recent years. It’s a sobering analysis of the new reality that these places are now only affordable for the wealthiest among us and, without extraordinary effort, they will bear no resemblance to the thriving, caring communities they once were.