I think so too jaycee. Imposing it as part of a condition on a lease amounts to a de facto garnishee order on the Centrelink payments. Good luck with trying to enforce that one.
The people who rent a $150,000 property are probably going to have much more difficulty paying your rent / looking after your property. People who are on Centrelink benefits and/or have no job. Less risk? 3 x trouble more like it.