Communications Agency Brown Bread is helping the art gallery promote the Our Own Ron campaign and get the funds together by November 5.
Director of Brown Bread, Jo Blair, said part of the brief Australian artist Ron Mueck received from the gallery was "cautiously optimistic", and she was feeling similarly towards the campaign.
"We're a little bit terrified, but we know Christchurch can do it. People can give $20 to $10,000 and we definitely need a few of those higher ones to make this thing happen."
The gallery had just under $800,000 before the campaign started. At two days to go nearly $190,000 was raised, with another $18,000 needed to meet the goal.
Blair found fundraising for an artwork that does not exist yet was a challenge to promote, because it was hard for people to donate when they did not know what they were getting.
A plan for the artwork was in place, but Blair's lips were sealed when it came to any details.
"I've had a little glimpse but I can't tell you or I'd have to kill you... I don't think it's going to look like Christchurch, but it's going to make people laugh."
The Ron Mueck sculpture would be the fifth in the "five great works" that the gallery was acquiring to mark the five years it was closed after the 2011 Christchurch earthquake.
The investment in this series of art would also build a $5 million endowment to help protect the Gallery's acquisitions budget.
Because the Christchurch City Council has a lot of different priorities it would keep the gallery off the chopping block and allow ongoing purchases of artworks, Blair said.
She said gallery director Jenny Harper approached Ron Mueck and his gallerist Anthony d'Offay for the final artwork because the Ron Mueck exhibition in Christchurch seven years ago was so popular.
"We always want to buy works that the community will all understand and will tell a story of this place."
The exhibition took place between the September 2010 and February 2011 earthquakes, during which time more than 135,000 people visited the gallery to see Mueck's sculptures, one of the Gallery's largest ever exhibitions.
It would be a new experience for Mueck, because he had never been asked to create a sculpture for a city before.
Blair said Ron Mueck visited in December last year and walked around the city talking to people on the street to get a feel for Christchurch.
Of the "five great works", two are from New Zealand artists and three are from international artists.
General manager for New Zealand touring agency Arts on Tour, and previously the Touring Manager for The Southern Regional Arts Council, Steve Thomas said he would like to see the Christchurch Art Gallery giving more support to New Zealand artists.
"I'm just concerned that a considerable amount of funds is going effectively offshore when it could be being put into our economy and our culture and our statements."
He understood the reasoning behind the Ron Mueck purchase and thought it was appropriate given its significance to Christchurch, but still believed the Gallery should give more support to local artists.
When he came to New Zealand from the UK in 1974 Thomas said it was obvious to him that there was something called a "cultural cringe" and he said it "seems to be carrying on with these purchases of the Gormleys and the Muecks".
The touring agency he manages, Arts On Tour, has solely toured artists from New Zealand for 30 years.
When asked about the decision to choose another overseas artist Blair said: "It's quite a bit of an issue actually, quite a few people are talking about it."
"It's not really my position to comment. The gallery team has an acquisitions committee and they have certain gaps in the collection and if they don't buy strategically now — for example they bought a Gordon Walters recently, I can't remember the price tag, but it was super inflated. And they could have bought it for £50 in the seventies, so they have to be really clever about how they use a small budget."
She said Harper wanted to "step up some of the works in terms of value and mark this time with a significant work that would be quite noticeable".
This will be Harper's last year, and Blair said the new director next year could have a completely different vision.
She also pointed out that the gallery bought from local artists throughout the year, but the Ron Mueck purchase stood out because of the scope of the fundraising campaign.
The artwork would take about a year to make, and it would be a couple years from the point of first approaching Mueck to receiving the end-product.