Korean stamps have two completely different issuing purposes, and for this reason there are two distinct methods of marketing. Before talking of marketing, however, we must first introduce the internal currency situation in the country. At the present time, three distinct types of currency circulate: the ordinary people use ordinary Won Then there is a currency exchangeable for US$, Japanese yen, etc., printed in blue which we will call the blue won One US$ buys 1.98 blue won. In addition, there is a currency, not freely exchangeable against U S dollars, etc., which is limited in use to the purchase of foreign goods. The bills are red so we’ll call them red won [Translator: It’s not clear how one acquires such currency.]

The distribution of those stamps issued specially for collectors is the responsibility of the Korean Stamp Company, internally and abroad. The Korean Stamp Company headquarters arc located near Pyongyang’s best hotel, the Korean. It holds a comprehensive supply of philatelic goods, and its principal clientele appears to be foreign collectors and tourists; blue won are used for all purchases, at a price of twice the stamps’ face value [Translator: I presume he is referring to mint stamps.] At the same time some hotels have bookshops which sell stamps; they also require blue won. Also, in these shops, incomplete sets are sold at face value; the writer managed to put together some complete sets from such purchases.
In March, 1995, Korea carried out a major revision of the prices of stamps; the selling prices of stamps from before 1990 underwent a rather large adjustment. The item most affected was the 1985 Kim IL Sung Visits China miniature sheet. Its original price was 10 Us cents. For a long time there was no supply; now it is reckoned at US$140, a 1400 fold rise.
Stamps for postal use are distributed throughout the country by the Post Office’s stamps division for all the post offices to sell. One can use ordinary money, or red won, for purchases at face value. Not many ordinary (regular) stamps are issued in Korea; one usually encounters commemorative stamps at the post office. The postal rates are simple; an internal letter costs 10 chon, with no distinction between local or otherwise, while a registered letter costs 40 chon. In a post office one can occasionally come across 10 chon stamps from commemorative sets originally issued for collectors. The selling price of the same stamp is either 10 chon or 20 blue chon, reflecting a potential 100% difference in price. For this reason the Korean government stipulates that foreigners in the country may not use ordinary currency, but must use red won or blue won.
(Extracted from Korean Philately, February, 2001 -vol. 47, No, 1)