The term 'philately' refers to the collection and study of postage stamps. The pricing in this field is done as per auction. The value that is ascertained before, is either an estimate; or is a calculated value based on an older sale price which was previously decided (based on another auction). This is done based on countless factors such as age and origin, place of manufacture, and the quality of ink on the stamp. The number of similar stamps in existence, is also taken into account. An auction is the place to get the best value and rates for any stamp collection. Factors Affecting the Value of the Collection Philatelic societies and clubs often publish what is known as a 'Collection Value Guide'. It helps an individual ascertain the value of a certain stamp. Here are a few factors that influence the value of a stamp. » Age and Origin The key factors that determine the value of any collection are the age and origin. The age of a stamp matters a lot; the older it is, the greater is its value. The origin of the stamp is another factor that thrills the collectors. Confirming the history, origin, and place of manufacture escalates the price of the stamp. Some of the best stamps that have high valuations, belong to former colonies, or really short-lived governments. Trial stamps, stamps with special watermarks, and stamp series always tend to fetch a high value. » Condition and Engineering The condition of the stamp is one factor that does not have any set rules. It matters during auctions, although collectors even purchase virtually illegible stamps at good prices. Engineering of the stamp goes hand in hand with the age. The art of printing stamps is unique and hence, several factors such as the watermark, ink, and paper of the stamp often tend to contribute to the price. » History Stamps are printed in a series, just like coins. Hence, stamps belonging to a particular series tend to bear a greater value than the others. The rule of thumb goes that the lesser the number of stamps in a certain series, the more is its price. The 'Inverted Jenny' of United States Postal Service is one such stamp. It depicts an inverted airplane (a printing error) and is worth a small fortune. Another one is the 'British Guiana 1c magenta' which is often regarded to be the world's most famous stamp. It was issued in British Guiana in 1856, and only one known specimen of this stamp survives. Another example is that of the 'Uganda Cowries' which were the world's first adhesive stamps. » The Era At auctions, collectors are ready to pay through their nose, to get stamps that are really rare, and are available in an entire set. Stamps from imperial colonies, short-lived states, and governments, are extremely valuable. The only reason of such a high value is that such series stamps were printed in limited numbers, and are very rare. The value of an international stamp collection becomes very high in case the stamp has been used in a certain time period, or to mail important letters or documents that played a significant role in history. For example, the value of a collection of US stamps escalates; if it contains pre-independence defunct stamps, limited edition stamps, or the ones that have printing mistakes. Thus, the history of the stamp and its entire journey in the world determines its value. There are a few collections which are regularly sold by collectors, such as President collection or the Princess Diana collection. The value of such collections tends to be extremely high.