Let me start by saying I am NOT an expert, nor do I have a collection that they would ever have. I have a a collection of mainly common coins that I have put in books or 2x2s and a lot of proof and mint sets from 1956 - 2020. I have had a few coins put in slabs, just because I am thinking some day they could be worth something. I collect for the fun, not for profit, My nieces and nephews enjoy coming over and changing my show case around to show different coins. Some day they will get the coins and I want them to know that if they like a coin then save it, and a coin is only worth what someone is willing to pay for it. So I really like proof sets, and 50 year old set are worth a whopping $10, but I love to show them off. I will never be selling my coins, so I buy what I like, not what the pro would get.