Changing New Zealand's flag is likely to cost the taxpayer $30 million or more, with Finance Minister Bill English acknowledging he doesn't know what the final total will be.
Just the buildup to the votes on the flag - and the referendums themselves - will cost $25.7 million.
Prime Minister John Key and Mr English yesterday confirmed details of the two-year process to select a potential successor to the current 112-year-old design.
Mr English will steer the process but a group of "respected New Zealanders" will be chosen to lead public debate on designs and come up with three or four that will be put to a binding referendum late next year to select a preferred design.
A second referendum in April 2016 will be held to choose between the preferred design and the existing flag.