Our analysis of Australian stamps covered some 2000 issues by Australia and its states between 1840 and 1950 which had achieved a ... Who would have guessed the most valuable stamp comes from ...

A Swedish stamp misprinted in 1855, called the Treskilling Yellow, is believed to be the second most expensive postage stamp. It was sold in 1996 for around $2.3m (£1.7m), ...