Are you only looking to do cash trades (Person to person)? Or do you accept other payment methods? Only asking because if you do accept other payment methods then you can simply load up those bitcoins in a wallet and sell them online without the paper, which would be much more convenient.
And if this is true:
isn't the price of each wallet little high? the bitcoin price is 415 to 420,. why you want to buy your paper wallet for 500$? I am just wondering. I didn't used paper wallet ever so may be your price is fair.
500AUD(Australian Dollar) is 384 USD (US Dollar) so it's undervalue.
OP if you found any buyer and he is ok to send first the money then it's ok, otherwise i would suggest to contact an escrow so both of you will be safe.
Then anyone would take it off your hands very easily for that discounted amount. But if you're only looking to cash trades, then try Localbitcoins and search buyers near you.