Brett Favre Q.B. Coin?

Okay I have a card of Brett Favre and it has "Pinnicle Mint Collection" written on it. it has pictures of Favre on it. In the top right there's a slot for a coin. I have the coin, its a little dirty but you can still see the writing and features on it. on the front in the bottom it says Brett Favre and a small football below that with a number 21 in it.(I don't understand that) Then around the edge it says "Four TD Pes In Five '96 Games." then in the middle it has a picture of Brett Favre. On the back around the edge it says "1997 Mint Collection Football." In the middle it says "Q.B. Club." and lastly in the bottom it says LIMITED EDIOTION in all caps. :D sorry that description was long but how much would this be worth?