The story has been told hundreds of times. Mom and Dad finally sell the old house, and all the childhood memories are unearthed from the basement and attic. And lo and behold, here's that box of baseball cards from the 1960's! After a few minutes of reminiscing about all your old favorite players, thoughts immediately turn to, "I wonder what these cards are worth?".

If you've just stumbled across a long forgotten box of baseball cards, the first thing to do is take a deep breath and gather some realistic expectations. While your baseball cards likely have some value, it'll pay off if you educate yourself on how old baseball cards are valued and priced.

Here are 5 key factors that determine what baseball cards are worth:

Scarcity of a card actually applies on more than one level. First, the age of the card. It stands to reason the older the card, the less likely an abundance exists in the market. Some fairly common baseball cards from the 1910's and 1920's fetch excellent value, simply because of time factors.

Next, scarcity applies in terms of the number of sets issued. Many card manufacturers of days gone by are long out of business. Further, some card manufacturers produced limited stock. As an example, historically speaking, Topps produced more cards than Bowman, so a Bowman player card would be worth more than a Topps card, all things equal. A little research will tell you the relative scarcity level of your cards.

In general, players who are inducted into the Baseball Hall of Fame are worth more than other cards. The best players offer the most appeal to collectors. Special cards, like rookie cards or those commemorating a milestone, also have added value. If you're unfamiliar with a player's relative status in baseball, a few minutes of online research will give you the answers you need.

Condition is probably the key factor of all. Many years ago, and quite by accident, I acquired the very desireable Mickey Mantle rookie card. However, the card was creased badly and had a small rip at the bottom. In short, the condition was poor, and selling it barely netted me enough for a decent dinner. A similar card in pristine condition would've netted a few thousand dollars at the time.

Take the time to learn, and understand, how a card's condition will affect value. Better to be educated than disappointed.

Here's another factor with multiple applications. Much like any collectible, the baseball card market is effected by economic conditions. Not so coincidentally, this is exactly the time many people look to sell their collections. This provides an opportunity for bargain hunters to set the market.

Also, be aware that certain players cards are worth more in specific geographical markets. As an example, a Chicago White Sox player card would tend to be worth most in Chicago. You should also research where a player was born, and look for collectors in that city or town. Chances are, you'll net a better price, particularly if the player was prominent.

Your price expectations are also critical. If you're looking at a retail price guide and your expectations match the listed prices, you're in for a disappointment. In general, expect to get about half the listed price. Remember, most big collectors are also card dealers, and they'll look to resell your cards at a profit.

If you're suddenly flipping through a long lost box of baseball cards, our advice is simple: Take the time to educate yourself about these factors affecting your card's value. Armed with a little knowledge, you can very well net an impressive sum for your cards.