WHAT IS THE VALUE OF 250gr, SOLID SILVER,LARGE COIN OF ATHENS 566 BC?

Answer 1

Do you mean the one with Athena on one side and the owl on the other? If so there are many different types by different mints and minters. You would have to take it to an ancient coin dealer. If you know the weight and date, you must know the value. For someone to be able to date it, one must know ancient coins. There are a lot of fakes out there also. An ancient coin dealer needs to see it.