Many people that are new to coin collecting do not understand how the coin market works and what determines the price and value of a coin. Unlike the retail market, for example a retail store where you may buy a jacket, the retailer buys the jacket from the manufacturer or distributor for approximately half of the price that you pay it for. That difference is what the store uses to pay the rent, the utilities, taxes and employees (the remainder is profit). If that jacket is selling well, the store can simply order more from the manufacturer.
For coin dealer, it is more complex. If 1913 Buffalo nickels are selling well, they cannot simply call up the U.S. mint in order more. They rely upon what has already been minted and what has been saved by collectors over the years. For coin dealer, this is his livelihood and his source of income that supports his family. In order to help you understand how this works I have written an article to explain what determines the value and price of coins.
Quick Links:Image Courtesy of: Heritage Auction Galleries, Ha.com