The reality of the federal budget for western Sydney school principal Chris Presland is three fewer teachers on his staff than he had planned for 2018.
The Turnbull government is increasing commonwealth funding to schools by $18.2 billion over the next decade but its plan falls short of the six-year commitments made by previous Labor governments.
Mr Presland's St Clair High School will get an extra $121,000 in 2018 under the federal package - less than the $417,000 initially promised by Canberra.
"It's almost like the federal government's taking $400,000 and giving us $121,000 and saying, 'Wow, look at the increase'," he told reporters in Canberra.
"It's really frustrating for people to try to understand the figures that are being thrown around, figures just dancing on a page."
Mr Presland had planned to employ four new teachers with the extra money.
Now he says he can only afford one.
Likewise, Colac Primary School principal Shelby Papadopoulos says while her budget will grow by $34,000 next year, it is almost $160,000 less than she had planned for.
She's been using the so-called Gonski funding to employ a speech pathologist and run an early-years literacy and numeracy intervention program.
Those initiatives would not be cut but they would not expand any further either, she said.
"That's what's really disappointing about this - we're currently just touching the tip of the iceberg here," Ms Papadopoulos said.
"We could make a huge difference if we had the funds originally promised."
Education Minister Simon Birmingham has argued his new funding plan should not be compared with Labor's deal but with the huge cuts flagged under Tony Abbott in the 2014 budget.
"Our plan is about giving all Australian schools a fair go and wiping away the 27 special deals Labor signed up that trashed the recommendations of David Gonski and his panel of experts," he said on Wednesday.
Mr Presland said he had believed the NSW government's six-year deal with Labor was a solid contract.
"That's what they signed up for and that's what we expect," he said.
Now he is pinning his hopes on the state government pressuring the commonwealth for a better deal.
Catholic schools have also raised concerns about the new deal claiming it could cost them millions.
It's a fight that should be avoided, according to Mr Abbott's former chief of staff, Peta Credlin.
"I don't think they need any extra fights and I would be trying to ameliorate this fight with the (Catholic) schools," she told a budget briefing in Sydney.
Former federal Liberal leader John Hewson disagreed, however, telling the PwC event the politics of Gonski 2.0 would "run really well" for the government and "some public barney with the Catholic school system probably won't hurt them either".
