The 1897 Red Revenue One Dollar Small stamp is the rarest of the Qing ... One went for over $1 million in 2008. A rare, unused green and violet 24-cent stamp with an inverted depiction of the ...

So, in 2005, Gross bought the also incredibly rare 24¢ Inverted Jenny plate block of stamps, accidentally depicting an aeroplane flying upside down, for nearly $3 million, and traded it for ...