Chinese Libation Cup: $75,640
In 2013, an anonymous Australian walked into a thrift shop in Sydney and discovered a rather strange looking cup. He decided the item was worth the $4 purchase price and he took it home.
After conducting some research it was determined that the libation cup was from 17th century China and carved from rhinoceros horn. The cup was taken to auction and sold for a life-changing $75,640 Australian dollars. If the true owner of this cup ever found out what they gave away they probably felt sick to their stomach.