Explore More: These 11 Rare Coins Sold for Over $1 Million For You ... That changed in 1966, when the country converted to Australian dollars and cents, similar to the U.S. system.

But some people believe that on the side that has Sir Henry's face, there is a defect with the word DOLLAR. "This decimal coin holds historical significance as it commemorates one of Australia's ...

So this one is the rare one." He said a recent selling price for a large head 10 cent coin from 1999 is $2.20, making it 22 times more expensive than its face value. According to Coins and Australia, ...

A rare 50 cent coin from the 1970s is worth up to $38 because only a relatively small number of them were minted.