"A $50 increase will mean that current students can focus more on their academic success rather than economic survival," NZUSA president Jonathan Gee said.
"With only a third of students eligible to access the allowance, the majority of students are still expected to borrow in order to live."
But the Aotearoa Students' Alliance said the extra money will simply be gobbled up by rising rents, and asked for it to be indexed to rent prices.
National's finance spokesman Steven Joyce said the Government should make the costings public.
"Where is the information on the cost of student allowances? Where is the expected extra write-off on student loans caused by this change? We know that Treasury and the Ministry of Education would have provided costings for this policy for it to go through Cabinet."
Asked about the cost, Hipkins said in a statement: "We will be releasing this detail when we release the fees-free policy in coming weeks (the two policies affect each other)."
In the election campaign, Labour said extra student support - including restoring student allowances for post-graduate students and those in long courses, such as medicine - would cost $270 million a year.
Hipkins said it was too early to say what the uptake would be for the extra loan and allowance money.
"I do expect the policy will boost demand for tertiary study over time. However, this expectation takes into account the current situation that student numbers across the tertiary education system were otherwise forecast to decline slightly over the next four years.
"My officials are currently working through the final policy details and we expect to make an announcement about student eligibility and how the policy will be implemented very soon."
He said that the rates of student loans and allowances will be inflation-adjusted from the start of April next year.
The Government is also on track to deliver the first year of fees-free education and training from January 1 next year.
