11 of the world's most expensive and unique art collections / Dealers are facing the tricky challenge of balancing artist and collector priorities / Artists offer to replace collectors' works lost in LA fires / Artists offer to replace collectors' works lost in fires / Los Angeles artists and collectors take inventory of charred works of art / Report: Art Collectors Are Changing Their Buying Habits / Collectors snapping up 2-year-old's paintings for as much as $7,000 / Meet the art collectors with home galleries: 'The stock market doesn't give me any fulfillment' / Art forger who duped collectors with fake Renaissance woodblock prints sentenced to more than four years in prison / China's growing stature in the art market fosters well-informed collectors, demand for advisory services from banks