im very private and secure with what i do and dont want to use exchanges, as i know its the best way right now.
Have you tried using Bisq? I don't know what the regulations is in Australia about this. Read it up first then try it. An alternative that involves some risk is a p2p with friends.
Do you have trusted friends that you know will not try to kidnap you if they learn of you wanting to do this, then request buy directly from them with cash while they send the equivalent to your Bitcoin wallet.