I just spent 2 days at a gun show. Many of these "instant gun appraisal experts*" were wandering about with firearms priced right at full retail". I used to try and tell them that if anyone at a gun show wanted to pay full price they'd go to a retail establishment where they would also get some type of guarantee to go along with it. When you're buying a gun from an individual it's usually "where is as is" and often hidden defects are discovered after the purchase has been made. What may seem like a steal at the time of purchase may very well not be in retrospect. When you're buying 75+ year old guns as many of us here do you are taking this kind of risk and this has to be factored into the finances involved in the transaction.
Jim
*This means they just looked on the Internet or elsewhere,found the most pricy example of their gun and regardless of condition, priced theirs at that level or higher.