One sold for £400,000 in 2010 ($535,000 today). William H. Gross was a famous stamp collector, and this 2 cents Hawaiian Missionary stamp was the most valuable stamp in his collection.

Could you have a penny worth way more than one cent? Or a quarter worth a small fortune?  A 1943 bronze Lincoln cent, a 1944 steel Lincoln cent, or a 1937-D 3-legged ...

The "Inverted Jenny," 1918, one of the rarest and most valuable stamps in the world ... started printing more than two million new 24-cent stamps with a special design celebrating the launch ...