In May 1958, Mongolia issued a 60-mung Globe and Dove stamp (Scott 143) to commemorate the Fourth Congress of the International Democratic Women’s Federation held in Vienna in June of that year.
The 2019 Scott Standard Postage Stamp Catalogue values the stamp at $5 in unused hinged condition. In unused hinged condition, this stamp is currently selling in the $40-to-$50 price range, eight to 10 times Scott catalog value. Examples in mint never-hinged condition sell in the $75-to-$100 price range.
This stamp would be a tremendous bargain if you found it offered anywhere near its Scott Catalogue value!
For non-philatelists: the Scott Catalogue, has been printed since 1840; it is the American equivalent of Britain’s Stanley Gibbons. Now comprising eight volumes annually, Scott provides a standard numbering system of every stamp ever issued.