My experience as a coin buyer only and not an expert is that many coins are overgraded. Beyond that, there are a lot of variables that relate to specific coin issues and their
quality. For example, I have seen
Judean coins graded VF that I would have graded
Poor in the grand scheme of things, but I have always assumed that is because the
Judean coins were
poor quality when they were minted compared to some other places. It is just so subjective and that includes coins that have been through a grading service like
NGC. I agree with David, either I want it or I don't want it and that is, for me, a combination of what I like, what I need for specific interests, and what I can afford. That said, the coin in my avatar (also posted in
Forum Purchase of the Day in the COTD section), was graded VF and I would have probably graded it EF. My only assumption on that grading is that it is off center, otherwise, that one is one of the best struck/best condition coins I own. So, I guess it could go both ways. Grading is one reason I have zero interest in modern coins and there are some interesting youtube videos about people breaking open
NGC encapsulations so they can resubmit the coin and
hope to get a higher grade that will make the coin more valuable.
Regards,
Virgil