I would agree that they likely would sell better there !! Here in the US many can be found on ebay at reasonable prices !! Just remember that a sale can be made or lost depending on the presentation !! The smaller cake stand is probably a petit four server for those little bite size sweets or finger sandwiches !! Would be great if you had three more of the desert plates then you could have a small desert set !! But at least you have the large cake stand and the smaller server !!
Since these were often decorated by amateurs it is common that there could be slight variations in the artwork !! Since you are in AU why not start the three pieces at $50. and see if it goes higher !!
Let me know how the sale goes if you decide to list them !! Good Luck !!