Yes many coin errors are worth big . Like the famous 1943 copper penny or double die verity’s are worth $$ . Most error coins can be found coin roll hunting which is fun look for them , can make you a a couple hundreds or thousands if you are luck to find some nice error coins
I'm sure you have lots of knowledge about coins and what to look for. I'm just starting out in collecting coins. I would really like to get metal detector and find old coins or perhaps buried treasure!!