Data this week showed the amount parents give to schools at a record high, with nationwide donations and fundraising up $1.2m from 2013 to 2014, reaching $161.6m. That's $8.4m more than in 2010.
With a review of school funding under way, debate is raging over where the Government should draw the line on school costs, and where parents should pick up the slack.
ASG Education Programmes chief John Velegrinis said he believed the state did a pretty good job.
"Parents can't walk away from educating their children. They are going to have to take part in it. They can't avoid the cost of shoes, uniforms, books," he said.
"Parents need to know it is a major life event and you do have to plan for it."
Secondary Principals Association president Sandy Pasley said the situation was fraught.
"Today's education is pretty hard for the Government to fund. But parents expect the very best so it places schools in a difficult position.
"I think what upsets schools the most is the parents who can afford to pay, but don't. We do understand when people can't afford it."
Ms Pasley said while things like sport were not funded by the Government, co-curricular activities were good for students to be involved in, and it was a disadvantage for students whose families weren't able to provide those opportunities.
Labour education spokesman Chris Hipkins said it would scrap donations altogether, and increase school funding to more sufficiently meet the need.
"There also needs to be equity around technology. We don't want kids whose parents can't afford the latest tech to miss out while others have iPads."
Education minister Hekia Parata said while extra-curricular activities helped children feel part of the community, some school activities, such as overseas trips, were beyond the reach of many parents.
She said it was up to schools to decide who paid for extras like camps, music and uniforms.
She did not want donations to be compulsory and said schools should not pressure parents to pay.
Dr Gasson's study found that while some schools exerted pressure, largely parents felt anxious because they thought the school activities were important for children's learning and their attitude towards school.
"Who wants to not let their kids go on trips when everyone else is?" one parent interviewed said.
" I go without to ensure my children don't," said another.
British research involving more than 2000 households found that school children who - because of poverty - were excluded from activities that their peers took part in were often embarrassed and bullied, meaning they were more likely to feel anxious.
Costs mount up but kids come first
With fourchildren, each at different learning stages, Auckland mum Alana Foster knows the pressure of back-to-school budgeting.
The Papakura family have one child at high school, one at primary, one at kindergarten and one at Playcentre this year - plus they need to pay for sports, and swimming, and the rest.
"It's just ongoing costs, and it can be really hard," Ms Foster said. "Particularly for the eldest one who's at high school because it was compulsory to have a device."
A particular sore point this year was a change in uniform for her 15-year-old, Leila, because she switched from the junior to senior school.
"I don't really see the point in that, but we still have to buy it."
However, Ms Foster, who is a stay-at-home mum, and her husband Paul, a truck driver, say they don't want their kids to miss out.
Sometimes, to help, they have opted out of paying school fees or paid them late to ease the burden on their budget.
"It can be stressful but it's better if you plan, and we've known it's coming up so we are prepared."
