@Spanik First, it is a medal, not a coin. It is very hard to find info about medals from private mints. They just don't keep those records. Chris
That's certainly one of the best silver rounds that I have ever seen! But's its still just that. A Silver Round. However, I would be surprised if that particular design didn't consistently command a premium over and above the price of 1 oz of Silver.
Silvertowne has their own minting services. Most likely a custom made piece you have. http://www.silvertownemint.com/
About whatever the spot price of silver is at the moment. No premium value. And a coin shop or pawn shop will pay a little less than that.