The Government expected to spend $36.50 per dose of Pfizer vaccine and had set aside almost $1 billion to pay for shots, according to a recent report.
Documents obtained by Newsroom, which date back to last March, April and May, indicate the 10 million doses of Pfizer vaccine that had been purchased from the manufacturer would cost a total of $365 million - or $36.50 per dose.
For other vaccines, the Government reportedly agreed to pay $80.6m for AstraZeneca vaccines ($10.60 per dose) and $384.7m for Novavax jabs ($35.89 per dose).
It had also saved $85.5m for Janssen's one-shot vaccine, worth about $17.10 per shot, according to Newsroom.
The documents were reportedly released by Covid-19 Response Minister Chris Hipkins in error through an Official Information Act request Newsroom made regarding the country's vaccine portfolio.
It is reported the documents were provided despite being listed as withheld.
Government officials have long kept the price of vaccines secret, citing commercial sensitivity.
Chief Ombudsman Peter Boshier weighed in on the issue in October last year after OIA requests for vaccine prices and shipment plans were denied by the Ministry of Health.
Boshier outlined how the ministry had refused the requests as it believed the release of such information would "unreasonably prejudice the commercial position of the person
who supplied the information".
Boshier deemed the refusal valid, saying: "Making that information available would have an adverse impact on the security of New Zealand's Covid-19 vaccine supply, both now and for the future".
"The potential consequences should New Zealand's access to Covid-19 vaccines be compromised would be severe," Boshier said.
The NZ Herald has contacted Hipkins' office for comment, as well as the Ministry of Health.
Newsroom's report said more than $950m had been earmarked to buy vaccines, including the Government's $35m donation to the Covax fund - aimed at ensuring equitable vaccine access across the globe.
The report stated New Zealand's price per Pfizer dose (US$25.50 in late March) was similar to other countries' - Israel (US$23.50), United States/European Union (formerly less than US$20, now around US$24).