Australian mint always have premium example is gold soverign coin some 8 grams coin Adelaide Sydney and Perth mint r valued anywhere between 2 to 10 times. It's bullion value
Another example Sydney mint10 pound coin 4 soviregnn coin 1887 date which value 10 times more than London mint version which is around 5000 dollars half million for 32 gram coin that is numismatic value
Even gold bullion minted by private jewellers from India london usa per 1970 have at least 2 to 3 times bullion price in numismatic auction