Value based on Condition
Silver coins are made of 90% silver prior to 1965 these coins have been in circulation many many years and as a result have worn thin over time.
Often times they were pulled out of circulation by those who knew their value would increase over time. However many silver coins can still be found as they continue to be spent and become thinner and thinner with time. this diagram shows an example of what it looks like when the exact same amount of coins are stacked next to each other those on the left have been spent in circulation and thus have worn thin compare the left stack to the right stack with the exact same amount of coins accounts for much more silver as each coin is thicker because it has not been put in circulation and has not been worn thin those will have more value than the others who have which have been worn down.
So, if you are buying or selling silver coins this example shows how value is based on the condition of the coins and as you can see those that have been spent and and worn diminishing value due to the loss of their silver this is a prime example of how the condition of a coin plays the role in evaluating the resale of an item.