Hi Ilayaraja --
You have a modern reproduction of an ancient Greek coin. The owl is prevalent on coinage from the city of Athens.
A genuine coin is pictured on this page:
Yes, Ilayaraja --
There is a market for fake coins. Their prices are, of course, very low compared to genuine coins. Here is an example:
Your Greek Athena coin might sell for $10 to $20 US dollars to a collector of such novelties.
Go on eBay and look for coins sold with 'replica', 'reproduction', or 'faux' in their titles.