Currently the Swedish "Treskilling" Yellow, or 3 skilling banco color error is the most valuable stamp to have been sold recently, selling for over 2.5 million Swedish Kroner the last time it changed hands. Only one example is known, but it is possible that there are others.
Although it hasn't been auctioned in a long time, the unique British Guiana One Penny Magenta is estimated to have a value of between seven and ten million dollars and sold for $9.5 million at Sotheby's in New York that last time is was sold.
2 dollars
bioootch
$40,000
It is £27856875666996
a motor bike
fender
100000$
It might be a Choprad
newbery
950,000
George Walker Bush