Some organ donors may have a heart of gold, but you cannot expect everyone to give you a kidney for free, says a think tank.
In a new report from the New Zealand Initiative, author Elizabeth Prasad says the Government could cut its health care bill significantly by compensating kidney donors better.
Donors now are paid between $140 and $350 a week for up to 12 weeks for time taken off work.
Ms Prasad's research has found the Government would, in some cases, save up to $120,000 in medical costs per operation if patients could have transplants, rather than continuing treatment such as dialysis.
The report says average income was nearing $1000 a week in 2014, so donors are essentially paying to donate under the present regime.
New Zealand Initiative head of research Eric Crampton said an increase in compensation would be a win-win for all parties.
"Usually policy is about trade-offs," Mr Crampton said.
"When the Government provides a favourable new scheme, it's either at the expense of another policy or taxpayers' wallets.
"In this case, the Government can do well by doing good. Compensating live organ donors fully for lost earnings is a fantastic bargain if it allows more people to provide that gift."
Kidney transplants make up about 65 percent of all transplants, but there is a significant shortage of available kidneys.
There were about 2500 people on dialysis in 2013 - at a total cost of about $150 million - while only 115 kidney transplants were performed that year.
A bill by National MP Chris Bishop aimed at increasing compensation for donors is expected to have its first reading in the Parliament today.