I noticed this is your very first post - so, Welcome Aboard! You didn't list your state (or country) in your profile. So, you might consider jumping over to Sub-Forums: Select Your Area.... and selecting your state for information (i.e., clubs, hunts, finds, legends, maps, etc.) directly related to your state (or country).
Now, back to your question - it would help if you posted a picture. Seeing that you haven't (until a member pipes in) - a good starting point (IMHO) is to search EBay and see what coins (like the one you found) are going for...