These coins are still in circulation so, unless they are part of a proof set or are uncirculated and in absolute mint condition, they are worth 50 cents.
The Australian 2001 issue of 50 cent coins was a "commemorative" issue for the "Centenary of Federation". There were 10 different designs issued. One each for the 6 states, 2 territories, Norfolk Island and another based on the traditional design.
An Australian 2001 cupro-nickel 50 cent coin (QE II)(Centenary of Federation), uncirculated and in absolute mint condition could fetch up to $6 AUD.
There were at least 2 million of each type minted.
A reputable coin dealer will be able to give a more accurate valuation.
Such a coin does not exist. The first Australian 10 cent coin was issued in 1966.
Such a coin does not exist. The Australian 2 cent coin was first issued in February 1966.
There is no Australian 1954 20 cent coin. Decimal currency was introduced in 1966.
There is no Australian 1950 20 cent coin. Decimal currency was introduced in 1966.
Such a coin does not exist. The first Australian 20 cent coins were issued in 1966.
Such a coin does not exist. There were no Australian 1967 50 cent coins minted.
Such a coin does not exist. The first Australian 20 cent coins were issued in 1966.
Such a coin does not exist. The Australian "cent" coins were first introduced in 1966.
Such a coin does not exist. The Australian 2 cent coin was first issued in 1966 on the introduction of decimal currency.
Such a coin does not exist. The Australian 1 cent coin was first issued in 1966. The Australian One Penny coin was issued from 1911 to 1964 inclusive.
Such a coin does not exist. The first Australian 2 cent coin was issued in 1966.
The Australian 2 cent coin was introduced at the changeover to decimal currency in 1966. There were no Australian "cent" coins minted prior to 1966.