The world’s rarest stamp is the British Guiana 1c Magenta which was introduced in 1856. The price of this stamp was $9.48 Million and it is considered the most valuable or rare stamp in the world. Moreover, other rare stamps include Treskilling Yellow (1855) which sold for $2.6 Million, the Sicilian Error of Color (1859) which sold for $2.6 Million, and Baden 9 Kreuzer Error (1851) sold at €1.31 Million.