Inverted Head 4 Annas is considered to one of the most valuable Indian stamps. It was one of the first multicoloured varieties in the world that was issued in India in 1854. The stamp is also so special because of the error: the head of Queen Victoria was printed upside down on exactly 206,040 copies. The mistake was discovered in 1890 and only 28 examples are now known to exist today. Inverted Head 4 Anna was sold for $170,500 at Spink in October 2010.