2015 One Hundred Pound Silver Proof Coin Coin BUNC In a Royal Mint Pack,, getting scarce due to popularity, 0.999 Silver Purity ,,,2OZS In Weight. The item "2015 One Hundred Pound £100 Silver Proof Coin Coin BUNC Buckingham Palace" is in sale since Tuesday, February 12, 2019. This item is in the category "Coins\Coins\British\Decimal Coinage (c. The seller is "goldstar4uu" and is located in Aberdeen, Aberdeen City. This item can be shipped to United Kingdom.