There were no Australian Coins minted prior to 1911.
With the possible exception of traders tokens (with the traders business name on them), there were no "Australian" coins minted prior to 1910.
The only coins circulating in Australia prior to 1910 were British Coins.
With the possible exception of traders tokens (with the traders business name on them), there were no "Australian" coins minted prior to 1911 and there were no coins minted in Australia prior to the opening of the Sydney Mint in 1855.
The value of a 1799 coin depends on the coin's denomination such as dime or quarter. It also depends on what country the coin came from, where it was minted and the condition of the coin. Without that information, it is impossible to state a value.
The value would depend upon the denomination and the condition of the coin.
its fake o silver dollars were made in 1799
Please post a new question with the coin's denomination.
The first Australian Dollar coin was issued in 1984.
Such a coin does not exist. The Australian Two Dollar coin was first issued in 1988.
Such a coin does not exist. The first Australian 10 cent coin was issued in 1966.
Such a coin does not exist. The Australian One Dollar coin was first issued in 1984.
The first Australian Two Dollar coin was issued in 1988.
The first Australian "Baby" coin sets were produced in 1993.
Such a coin does not exist. The Royal Australian Mint has never produced a Two Pence coin.
Such a coin does not exist. The Australian 2 cent coin was first issued in February 1966.