Their value is historical and does not vary significantly. These cards, like art, will only grow in value with time. So, with the Major League Baseball playoffs quickly approaching, there is no better time to get started. Whether you are looking for an investment or want to start a collection, baseball cards are a great way to connect with players from years past through today's stars. Baseball cards come in three main types: modern-day cards, vintage cards, and holograms. Modern-day cards feature photos taken by professional photographers during regular season games. They are signed by the players and usually carry a number between 1 and 99. These cards are the most common type found in grocery stores and card shops and can be bought for as little as $1 each. Vintage cards are not sold in retail stores but instead through online auction sites such as eBay. Vast quantities of these cards were produced throughout history and many have become extremely rare. Holographic cards feature two-dimensional images printed on plastic sheets that are mounted on cardboard backing. These cards first appeared in the 1980s and are becoming more popular every year. Over the course of time, the values of all types of cards will fluctuate due to demand and supply. If you buy cards that rise in price, you will see profit after cost.