Greek coin from grandmother's dowry

This coin was part of my grandmother's dowry and was made into an earring worn by my mother.  How much is it worth? Is it rare?  According to the link on this website, its rarity is rated at 97 but I am not sure if that really makes it rare.  The coin is in excellent condition outside of it being made into an erring.  I believe this might be a gold coin.

N#330070

You have correctly identified a commemorative medal (not a coin), some links below will help you answer your questions about the NRI and it’s worth.. They are from the FAQ section. If it is gold, a jeweller will pay about €1000 for 10g of gold.

https://en.numista.com/help/what-is-numista-rarity-index-nri-79.html

https://en.numista.com/help/how-much-is-my-coin-banknote-or-piece-of-exonumia-worth-31.html

It's not the medal you identified. Looks to be part of this series Liberation of Thrace and Asia minor but not in the Numista catalog.  Gold melt value will depend on the weight and purity.