Age--The Older the Better, Usually

• The most valuable comic books date from the Golden Age of the 1930s to the 1960s. Certain iconic characters, such as Superman, Batman and Wonder Woman, were all introduced in the 1930s.
  
  

First Appearances

• One trait to look for when assigning value is a character's initial introduction. For example, "Detective Comics" #27 from 1939 features the first appearance of Batman and is worth, in perfect condition, around $475,000. The preceding issue is only worth $5,000.
  
  

Condition

• A comic is rated based on how "perfect" it is, free from paper yellowing, tears, rusty staples and other signs of age and abuse.
  
  

Grading Comics

• CGC has become the authority in grading a comic and seals it in a plastic slab with its grade and evaluator notes.
  
  

Buying and Selling Comics

• As with any collectible, it is best to buy comics in person to better evaluate them. Sellers do post CGC slabbed books regularly on such websites as eBay, which gives the buyer more confidence in condition and value.