In 1956, Iran issued a stamp commemorating the tenth anniversary of the Iranian National Olympic Committee (Scott #1047). 30,000 were issued, and Scott '14 prices the unused stamp at $40.00.
The stamp has additional appeal both a a Sports/Olympics topical and as an Animal topical, due to the Persian Lion and Sun emblem.
I believe that the stamp is undervalued due to the unpopularity of Iran's stamps, a consequence of its pariah status. Currently, Iranian stamps of the pre-revolutionary period are primarily of interest to collectors among the Iranians living abroad, a relatively affluent group, of whom there are about 1.3 million.
Note that a common defect found on many Iranian stamps of the '50s is badly toned, "gloppy" gum. When purchasing #1047, endeavor to select examples with clean gum.
Stamps of Iran are not widely collected at present, partly for political reasons and partly because of the ubiquity of fakes among the early overprinted issues. Nevertheless, it is an oil-rich nation (ranked second in both oil and natural gas reserves) of 76 million people, and there are signs that many of them are becoming fed up with the corrupt and reactionary theocracy that is isolating Iran from the rest of the world. Furthermore, it is beginning to diversify away from its dependence on oil into other industries, such as biotech, nanotech, and pharmaceuticals, and it has the potential to develop a thriving tourism sector, should it institute reforms and begin to improve its image.
Those interested in learning about investing in stamps should read the Guide to Philatelic Investing ($5), available on Kindle and easily accessible from any computer.