Australian decimal coins, for the most part, aren't particularly rare, so don't really command high prices. I am going to assume you are talking about circulation coinage.
However, there are always exceptions to the rule.
For instance, a 2000 mob of roos $1 mule, which was struck with a 10c die obverse is rare and commands prices around $300 up depending upon grade. An uncirculated example will fetch over $5000.
A 1966 'wavy 2' will also fetch higher prices, from $100 up depending on grade, going up around the $2000 plus mark for higher grades.
Pre Decimal coins are a different story. Some are worth many thousands of dollars, with a high grade 1930 penny worth hundreds of thousands.
As Peter said, the most valuable thing you can buy is a good reference book.
However, there are always exceptions to the rule.
For instance, a 2000 mob of roos $1 mule, which was struck with a 10c die obverse is rare and commands prices around $300 up depending upon grade. An uncirculated example will fetch over $5000.
A 1966 'wavy 2' will also fetch higher prices, from $100 up depending on grade, going up around the $2000 plus mark for higher grades.
Pre Decimal coins are a different story. Some are worth many thousands of dollars, with a high grade 1930 penny worth hundreds of thousands.
As Peter said, the most valuable thing you can buy is a good reference book.





















