www.kidney.org.au/Transplantation/LivingKidneyDonation/tabid/691/Default.aspx
Info taken from this KHA page

Can I donate my kidney to a stranger? 
Non-directed live donation is a new form of living donation.  It means being a live kidney donor to a complete stranger.  Someone donates a kidney and allows it to be given to the most suitable recipient on the transplant waiting list.  As this is a very serious decision, you may need to talk about it with your family and friends, doctor, renal transplant nurse, social worker or counsellor.  Policies and guidelines are currently being developed in some states of  Australia.

Can I buy or sell a kidney? 
Trade in human organs and tissue is illegal in Australia and also ethically unacceptable.  Anyone involved would face criminal charges.  The illegal buying of organs overseas raises the risks of recipients contacting blood born diseases, complications or even death.