Jamie: in some ways, we seem to be opposites.
I built a pre decimal type set of Austrlain coins a very long time ago in all three metals, Adelaide Pound included. 17 sovereigns and halves with the silver and bronze types represented by the rarest date for type. (except the '30 penny, which was represented by a '25). Sold that collection, along with about 50 nice ancients including two gold, to raise deposit for a house.
Now, my U.S. collection is bigger than my current Australian collection! It includes a couple of nice early commemorative half dollars, a St-Gaudens Double Eagle and a gold dollar of 1853. I picked up a complete set of circulation States Quarters out of a bikkie barrel of change, when I visited the 'States recently. Cost? Face value, $12.50! That was fun!
The Canadian part of my collection, which includes a 1913 $10 gold, is about the same size as my Australian collection. It includes a type set of silver dollars to 1967, and a type set of nickels, including a tombac beaver, in Unc.
My current collection of ancients (which is my first love), is bigger than these. It numbers around 200, and includes a Macedonian gold Stater of Philip 11, aureii of Augustus and Vespasian, solidii of Leo and Phocas (Byzantine), and a tetradrachm of Athens, about 430 BC. Quite a few other nice tetradrachms as well. Ancient coins of Southern Asia, China and India are represented.
Such a collection needs decent library backup, and includes a copy R.I.C., all volumes, Krause
for the last 400 years, books on forgery (a must), and a complete set of David Sear's books.
Oh! I probably have the biggest collection of square coins by type in the World. Easy to do, because I have NEVER heard of anybody else collecting square coins by type! 84 machine struck types, and counting!