New Zealand lost 10 soldiers in the final years of the Afghanistan deployment at a time when Defence spending more than doubled.
In 2006/07 the Defence Force spent $22m, which rose to $33m and then $44m in the following years, before peaking at $50m in 2010/11. The increased cost is mainly attributable to the deployment of the SAS.
Labour defence spokesman Phil Goff said: "Those figures show the enormous cost of the war financially, and in human terms, and so little to show for it.
"This was a regime that was being upheld by drug traffickers and warlords, and is it worth sacrificing New Zealand blood to uphold people of that character? Increasingly it became obvious to me, from around 2007, that we weren't serving a purpose there any more."
The two Afghan soldiers whose families were paid were part of the Crisis Response Unit that New Zealand's SAS was mentoring.
The payments relate to deaths on August 19, 2011, in the same battle in which Corporal Doug Grant died. Another was killed on 17 July 2011, on the day Taliban forces assassinated the brother of Afghan president Harmid Karzai.
Goff said the payments were gestures "to those guys who had lost their father or husband and a form of income".