Rare British Guiana Stamp

The rarest stamp in the world is the 1856 British Guiana 1c magenta stamp, of which only one specimen exists. It has broken the world record stamp price on each of the last four times it has been sold. It was sold for 6 shillings, £120, £150, $36,000, $40,000, $280,000, $935,000, and most recently for $9,480,000.