I think we are prepared to accept too little from our politicians.
We say to ourselves "We have to vote for someone, so I might as well vote for the pollie/party which is the least worst."
I see it differently. If none of the politicians or their political parties appears to me to be honest enough or trustworthy enough then I do not vote for the least worst of them and I don't vote for them because "otherwise my vote is wasted".
My vote is wasted if I vote for a party whose politicians have proven to be self-interested trough-guzzlers, time and time again.
My vote is wasted if I vote for one party of trough-guzzlers only to keep out another party whose feeding habits are identical.
My vote is truly wasted if I consider the politicians to be untrustworthy and corrupt and yet I vote for them anyway.
My vote is wasted if I vote purely from self interest, knowing that while the party I vote for may be good for me personally, it is bad for Australia and the majority of Australians.
In this latter case, if we vote for them anyway, then how are we any different to them?
Your obligation under the law is to turn up to the ballot booth and have your name signed off when you receive your ballot papers. What you do with those papers after that is a matter for your own conscience.