Universities have accused the Turnbull government of muddying the waters as it prepares for a fight over higher education funding.
Education Minister Simon Birmingham on Monday released figures showing what students will pay under planned changes would more closely match the benefits of getting a degree.
The federal government's overhaul of higher education includes increasing student fees by up to $3200 over a four-year degree, cutting university teaching funding by 2.5 per cent in 2018 and 2019, tying a portion of funding to performance measures, and lowering the threshold when student debts must start to be repaid.
Senator Birmingham said the report, prepared by Deloitte Access Economics, "injects facts ... into a debate that has at times been dominated by platitudes and sound bites".
It showed about 45 per cent of the benefits from a higher education were private, such as securing a well-paid job.
The government says its planned fee increase will mean students contribute 46 per cent of the cost - up from 42 per cent now - with taxpayers covering the rest.
Senator Birmingham took aim at university groups that supported the coalition's previous proposal for full-fee deregulation but oppose the package now before parliament.
They had "tried to walk both sides of the street in this debate".
The minister characterised the increase in funding to universities since 2009 as "a river of gold".
The group of six Innovative Research Universities disagreed, telling a Senate inquiry on Monday the river of gold was down to more enrolments, not any boost to per-student funding.
"If anyone's being inconsistent here, it's the government that previously embraced the concept we did need more resources," executive director Conor King told a hearing of the inquiry in Melbourne.
"In this (package) it goes down; of course we're opposed."
The Group of Eight - representing the nation's research-intensive universities - said the government's package was not coherent and would leave students paying more for less.
The government had a track record of releasing reports such as the Deloitte research to the media without showing the sector first, chief executive Vicki Thomson said.
"We find we're responding to claims about rivers of gold or vice-chancellors' salaries or surpluses which are muddying the waters when we're wanting to talk about actually what sort of university sector do we actually want in this country," she told the committee.
The Senate inquiry will also hear from the academics union, education department officials, business representatives and higher education experts on Monday and Tuesday.
It's expected to report when parliament resumes in August, clearing the way for the bill to be debated.