Most under rated Australian coins

[autocoupler]

Actually errors are another that seem very underrated

:agreed: Varieties, whether or not being intended or unintended ( not mint sport ) results of the minting process, have in my opinion been underrated by the majority of collectors in the past but are quickly gaining momentum as evidenced by auction results over the past couple of years. The pre decimal penny die combinations are my favorites, many of which are still out in the pond.  

[markn]

Can't you find the big head 20c in mint sets?

Yep, but they seem to be harder to find in circulation.

Yes, I agree.  But given you can find wonderful examples in mint sets why would anyone pay for a circulated example regardless of how hard they are to find?