Hi Flinders, If you're going to buy coins look for bullion coins - coins priced at spot plus a set mark up depending on qty and keep an eye out for the mintage numbers. Some bullion coins like the Perth mint lunars and kooks are minted in limited numbers. This means you can purchase them at a bullion price with potential for a collectors premium when they sell out.
There are dealers in every state that you can buy off cheaper than the mint when you're purchasing coins by the box.