True bullion will have a purity rating of 99.99%. This 2014 1 oz Gold Buffalo $50 Coin PCGS MS69 FS (Black Diamond Label) is proudly minted by the U.S. Mint.The United States Mint was founded in 1792 … 2011 $50 Gold Buffalo Tribute Proof: Obviously, this coin does NOT have a face value of $50.00. PCGS Graded 23 of Top 25 Most Valuable U.S. Coin Value Price Chart for Gold American Buffalo Bullion Coins. This latest annually issued one-ounce coin features a composition of 24 karat gold and is available today for $1,640.00, the lowest starting price since 2010. //