Learning Articles › All About Mystic › The rarest U.S. stamp will be sold June 14. Have you seen our video about Mystic owning the stamp?The rarest U.S. stamp will be sold June 14. Have you seen our video about Mystic owning the stamp? I bought the stamp in 1998 to show to collectors. I paid $935,000! Here is a link to my video telling the story. Here is a link to all Mystic videos on stamps and collecting See All Videos Share this Article