Such a coin would have been issued as part of a mint or proof set.
Any value would depend on the metal it was struck from and the design of the coin.
The Australian Koala series of coins were only ever minted in platinum and the Twenty-Five Dollar coin was only ever issued as part of a set.
The Royal Australian Mint never issued a Twenty Dollar coin until the 1990's and then usually in a mint set of bullion coins.
1848. Silver. Twenty. Dollar. Coin
The first Australian Dollar coin was issued in 1984.
Such a coin would have been issued as part of a mint or proof set. Any value would depend on the metal it was struck from and the design of the coin.
Such a coin does not exist. The Australian One Dollar coin was first issued in 1984.
Such a coin does not exist. The Australian Two Dollar coin was first issued in 1988.
The first Australian Two Dollar coin was issued in 1988.
The denomination of the gold McKinley Memorial coin is One Dollar not Twenty. Value is $700.00-$800.00
Both
4000.00
An Australian 1987 fine gold 1/4 ounce Twenty-Five Dollar nugget coin (Elizabeth II), uncirculated and in absolute mint condition and the original packaging, could fetch up to $375 AUD. There were 13,692 minted. A reputable coin dealer will be able to give a more accurate valuation.