Purchasing Kennedy half dollars in mint condition should be your goal, since the state of a coin is really important to its worth as a collectible. Any coin which is damaged, marked, scratched, or scuffed will usually suffer a serious reduction in value compared to a coin in finer form. Collectors should consider more than just a coin's age to determine its value. Of course age and rarity make a coin more valuable to collectors, but they aren't the only factors that matter. When thinking about market value for a particular coin, always try to assess the demand.