That's just marginally more than the impact of the Canterbury earthquakes on the New Zealand economy.
But unfortunately for us, there's no insurance companies around to help fund this increase.
It has to come from the taxpayers' pockets and the amount that has been tucked away in the NZ Superannuation Fund.
Right now the super scheme kicks in at 65 years for everyone. Low-paid workers or millionaires - everyone is entitled to it.
But like most Western nations the lack of sufficient younger taxpayers coming through to support future state-funded super payments for older people who may live on in retirement for 20 to 30 years makes the National Superannuation Scheme unsustainable.
I'm taking Prebble at his word when he says he has come out of political retirement "because Parliament needs at least one party willing to ask the question, where is the money coming from for all these political promises?"
The Prime Minister has boxed himself into a corner on National Superannuation.
He may not have been quoted strictly accurately along the way.
He may even have been a bit clumsy in his sentence construction.
But the upshot is that Key is widely reported to have made a pledge that he will resign as Prime Minister rather than see the national super age go up on his watch.
Who better than Prebble to spot a potential wedge between National and Act and create a groundswell in favour of raising the superannuation age that sufficient voters see the point of doing so (and sufficient younger voters become concerned at the numbers of retirees they have to support along with paying the out-landishly large mortgage bills which cripple their finances).
Key can't do this. But Prebble and Act's new leadership can. Treasury - along with a bunch of external advisers - has recommended that New Zealand fall into line with other similar nations who are raising the age of entitlement to state pensions to take account of the longer lives that people live now compared to the time when governments decided it was a good thing to do to look after people a bit in their old age.
It is complete nonsense to expect people to contribute taxes for 30 to 35 years of working life, then expect the state to help underwrite another 20 to 30 years of life.
This could all change, of course, if explorers struck oil and gas in sufficient quantities here to underpin a huge wealth fund like Norway has. But there is no sign we are about to be oil sheikhs of the South Pacific quite yet. Pity.
It's instructive that when Key was yesterday appraised of new Act leader Jamie Whyte's statement that the National Party "lacks courage" on the retirement age issue, Key did not immediately box himself back into his corner.
He simply reiterated he was "comfortable" with the cost of the scheme - this is expected to peak at 8 to 9 per cent of GDP when all the baby boomers come on to it - and wasn't planning a review any time soon.
Whyte also talked sensibly about the looming issue of healthcare affordability. But short of refusing medical treatment and operations for those above a "certain age" there's probably not a lot that can be done there.
Unlike the ancient Inuit (who may well have rescinded their noble policy decades ago) we have not built a legend around older people "going out in the snow" to take the burden off their kin folk.
The Government's stance - reiterated by Finance Minister Bill English this week - does make New Zealand an outlier when it comes to G20 finance issues.
Australia is poised to follow Britain's move to raise the state pension to 70 for those currently under 30.
Already it is on track to raise the age to 67 by 2023.
At least Australia has ensured its citizens build substantial retirement funds through the compulsory superannuation. We don't even have that.
Labour also wants the age raised but has yet to spell out the carve-outs from the policy which means some people will have an out.
United Future's Peter Dunne also wants a more flexible system.
Prebble and Whyte have done the New Zealand taxpayer a favour by making this an early election issue.
