New Zealand will never again be able to afford to host the Rugby World Cup, the country's foreign minister says.

Murray McCully said the 2011 World Cup "may be the last time our small country of 4 million people can afford to host a rugby world cup".

Hosting rugby's premier tournament is now expected to cost organisers $39.3 million.

The Government is paying fees for hosting rights and has also funded state owned broadcasters to secure television rights to the tune of over $3m. Central and local Government have also chipped in millions to upgrade stadiums around the country.

Meanwhile, Rugby World Cup organisers say the benefit to New Zealand businesses will be $500m.

In Auckland alone, Rugby World Cup spokeswoman Joanne Perry said businesses will benefit by $267m during the six week tournament window. She said that figure includes money paid by the organisers.

Speaking at an event at the Hong Kong Sevens tournament at the weekend, Mr McCully said the country is "giving it everything we can".

Just what the Government will gain from a likely increase in GST takings, generated from higher overseas visitor numbers, is not known.

Earlier this month, John Key announced that he would not be backing Auckland's bid to host the 2018 Commonwealth Games.

Mr Key said the Games would come with a $600m price tag.

- NZ Herald staff and AP