A price guie is a book or online site that attempts to deliver accurate and concise valuation information for a good. Many industries and hobbies rely heavily on independent pricing sources when evaluating an item to sell or to purchase. This is most prevalent in the automobile industry and in the world of collectibles such as baseball cards, coins, comics, or stamps. Not only do vendors rely on these guides when determining at what price they should list an item for sale, but interested parties look at price guides when shopping.