Collectible coins, particularly those from the United States, can vary widely in value based on factors such as rarity, condition, and demand among collectors. A specific type of collectible coin is the 2006 Philadelphia mint dollar, which often comes in rolls containing a set number of coins. Coins produced in Philadelphia carry a "P" mintmark, indicating their origin, and can be sought after by numismatists for both their historical significance and potential investment value. Collectors often pursue complete sets or specific dates to enhance their collections.