I collect coins too! Hydra rulz.
I have a bag full with about 15 pounds (6.5 kgs) of coins. A lot of them are "discontinued" coins, replaced by Euros and other new styles, but they're shiny and metal and I had no intention of selling/spending them anyway.
I want all the Euros reallyreallybad! And I'm envious of your 10c collection--AU/NZ coins are expensive and hard to find (cheap) on eBay. Probably because they're current (like the Euros).
I collect "foreign" coins though--I have a really hard time collecting American money.