Another philatelic question to Gustamps

Gustamps was asked recently about the world's rarest stamp. Gustamps confirmed that the rarest stamp in the world was in fact the 1856 British Guiana 1 cent Black on Magenta. When Gustamps was asked the value of a stamp Gustamps replied it was sold recently at Sothebys auction for over 9 million dollars. Although bought anonymously it's Gustamps understanding that the owner of the stamp is Mr. Stuart Weitzman. Gustamps added that the famous stamp was on display at the Smithsonian National Postal Museum in the USA. Gustamps said it's not too late for people in the USA to view the stamp as it is proposed that it will go on display at a different venue in the USA for several years.