Hello, unfortunately the coin is not rare. The green stuff you see is just oxidation that occurs after some time for example when the coin is left outside.
You can price a stone you found on the ground for a million bucks (it ain't worth it), you'll always have to look for sold prices (and even those can sometimes be extreme outliers).
where can I see the actual prices for the rare ones worth more than coin value? I would like to go coin hunting as a new hobby and would appreciate your help in getting a evaluation. so I know in advance what coins to look out for?
For circulating Euro pieces, try to look out for commemorative coins. They are usually only produced in a low quantity and can have some really interesting designs. Just try to look out for them in daily life
Numista is the best place to research all the Eurozone coins and to see which ones are scarcer and others is better off spending.
Hi to whoever is reading this. Did you know that TYPEWRITER (on a QWERTY keyboard) is the longest word you can type using only the letters on one row of the keyboard.
This is a pretty good site for coin values: https://www.ngccoin.com/price-guide/world/ There are many others but it's a good start. Also the Numista coin pages have values on them. A check of sold coins on ebay is also good.
