Doug,
While Jay has given a great link to a coin like yours, please don't think this is a $500 coin. Although specific values aren't discussed here, I can see that by 2 posts you are new to this and therefore the following info may be of value:
a.
Ancient coins are not as valuable as one first thinks. Of course, there are exceptional coins out there commanding premium prices (like the example Jay linked), but your example doesn't fall into this category; and
b. An ancient forgery will not command as high a
price (generally) as would an official issue.
With your example, I would treasure it as a keepsake, or use as a springboard into a new hobby.