What is the value of a 1997 Eire 50 Pence coin?

There is no such thing as a 1997 Eire 50 Pence coin. Ireland uses Euros, and has since 2002. In 1997, Ireland used the Irish Pound. There were no 50 Pence coins minted in Ireland in 1997. They were minted from 1928-29 and again in 1969-1971, all with the same design. The value of a 1997 Eire 50 Pence coin is therefore zero, as it does not exist.