Korea, 1950, 150wn Green, tied by purple Seoul, Korea cds on airmail cover to Garden City, N.Y., Very Fine. Scott No. C3  Estimate $500 - 750. A Linn's article from July 2, 1979 describes this as one of the rarest stamps of Korea to find on cover, with one from a 1979 offering at auction realized $1,200. $0 (Image)