SELL BASEBALL CARDS FACT

The rare baseball cards are the ones which are difficult to find and also the most expensive ones. The rare type of cards are the oldest baseball cards and those from limited edition sets. A rare card generally must be kept in good condition in order to be valuable, although the rarest cards can be worth tens of thousands of dollars even in poor condition. Price also increases if there is an autograph on it. Rare baseball cards or the vintage baseball cards do not have a certain price established. Their value is judged upon their quality, condition, rarity and upon the number of collectors that are seeking them.
http://en.wikipedia.org/wiki/Baseball_card
http://creativecommons.org/licenses/by-sa/3.0/

Other Types of Collectible Cards:
Cigarette cards, Football card, Hockey card, Rookie card, Sports cards, Trading cards