The mint looked at the 400 million official gold sovereigns it churned out between 1855 and 1931 and determined what coins have the greatest numismatic value and dropped it into a handy chart. Best you get these coins to a dealer rather than save them for financial armageddon:
This table reveals the rarest dates of nine different types of Australian sovereign. Any of these years could generate a reward considerably higher than the coin’s bullion value, particularly if it’s in top condition.
Jon Nadler lauded the Perth Mint certificates as a good way to hold gold in an interview with the Gold Report.
"The Perth Mint certificates and the Kitco Pool accounts, for example, all offer the same exact physical gold, albeit it in the form of a large bar of which you own a portion, but at prices that are much, much superior vis-à-vis small coins or bars," said Nadler.
Chart and coins from the Perth Mint