Do you ignore yard sales?

According to Sotheby's appraisal, the bowl pictured here dates back to the Ming dynasty of the early 1400's. Of six other bowls of this kind that are known to exist, two are in the National Palace Museum in Taipei, Taiwan. Two are in museums in London, and one is in the National Museum of Iran in Tehran. None are in the United States.

Last year, an unidentified Connecticut man paid $35 for this bowl at a yard sale. Then he sent its picture to Sotheby's, where an Important Chinese Art auction was held this month. His yard sale bowl was auctioned off for $721,800.