Recently, a respected art collector in Portland, Ore., walked into a local gallery. The owners greeted her warmly, and ushered her to the back room to show off their latest acquisitions. After politely declining several works, the collector chose a $5,500 porcelain sculpture shaped like a basket and covered in tiny, platinum elephants. "She has such a great eye for art," gushed the gallery's co-owner, MaryAnn Deffenbaugh.

The...