How much is a galeon?

Excuse me, could you please clarify for me the value of a galeon in today's market? I understand that it was a form of currency used in the past, but I'm curious to know if there's any modern equivalent or if it's still considered a viable means of exchange. Additionally, is there a specific method for determining its worth, perhaps through historical records or expert appraisals? I'm quite intrigued by this topic and would appreciate any insights you may have.