Hi Panos -
It is a replica of the old, old coin in my picture: a gold pound of Elizabeth I, who reigned Great Britain from 1538 to 1603. I can't read the Greek, but I think that is what it says.
The genuine coin in my picture is an amazing example from Heritage (we thank them for use of their coin photo). It sold for $200,000 US dollars in a recent auction.
Your coin, as a replica, is worth its weight in gold. I think the Greek says 11 grams of 22 karat gold. Since 24 karat gold is pure gold, the total gold content of your coin is 11 x (22/24) = 10.08 grams. And, since there are 31.1 grams in a troy ounce, you have (10.08/31.1) = 0.32 troy ounces of gold.
The current price of gold is $1717 US dollars per troy ounce. Therefore your piece is worth 0.32 x 1717 = $550 US dollars.