The use of coins dates back to ancient times, and they have been with humanity ever since. Coins stayed in usage even after the world adopted paper money. Coins offer a sense of permanence and history that bills lack. This is especially true of the gold coin. Coins of any material that are kept safe for a long time tend to increase in worth.
Many coins no longer in circulation are of great interest to coin collectors. Also called numismatists, these collectors love old and rare coins. Gold coins are especially popular. This is because the gold coin has a high collection value, and an even higher market value. They can be worth hundreds of dollars. Certain rare coins can be worth thousands, or even millions, of dollars. American monetary history is full of rare coins in high demand by collectors. Some of the more famous coins include the gold and silver buffalo coins, or the renamed St Gaudens Double Eagle. Coin collecting is a popular hobby, so there are many sources (in the form of books and websites) supplying information about the value of specific coins.
There are many ways to get these rare coins. Sometimes, people find them lying around the house. It's easy for someone to drop a coin and completely forget about it. Of course, the collector can not rely on finding a rare gold coin in his or her house. Auctions are another method of obtaining rare coins, though these can get quite expensive. Perhaps the most convenient way is through a website.