Some Illawarra TAFE teachers are worried their courses will attract too few enrolments to go ahead from next year, when widespread fee hikes are introduced.
Fees for most students at TAFE and private colleges will increase in 2015 under a sweeping overhaul of the state's vocational education system.
Students on concession fees paid $53 to attend TAFE in 2012; in 2015, the cost will be up to $240.
For a diploma of electrical engineering - now priced at $1514 a year, and usually completed in two years - the fee will skyrocket to $8190.
NSW Teachers Federation organiser Rob Long said Illawarra TAFE teachers were concerned the new prices, announced last Thursday, would deter some students from enrolling and make it unviable to run certain courses.
"A number of teachers I've spoken to say they can't see that their courses will get up," Mr Long said.
The union is calling on NSW Education Minister Adrian Piccoli to reject the changes, particularly in light of incoming reform at a federal level that will mean rising living costs in several areas, including charges to see the doctor.
Those federal changes also include tough new "learn or earn" rules, whereby people under 25 will be denied the general unemployment benefit and pushed onto lower-paying Youth Allowance.
"The world has changed since that budget," Mr Long said.
"If it's 'earn or learn', then investment in TAFE NSW is going to be vital, and this privatisation won't work.
"The federal government are saying they're going to get people off the disability support pensions. Now the [state] Minister for Education is not going to give the same level of support [offered] in the past for disabled students coming to TAFE.
"The state government and the federal government aren't working together on this one."
Concession prices will be eradicated for diploma and advance diploma courses, including for students with a disability, who will be referred to the student loan system.
Training organisations will receive a 15 per cent loading - several hundred dollars in the case of many certificate-level courses - to pay for assistance for disadvantaged learners.
The loading is higher than the expected 10 per cent, and has been welcomed by TAFE NSW managing director Pam Christie.
"This will enable TAFE NSW to continue our support of people from disadvantaged groups, including Aboriginal people, people with a disability and the long-term unemployed," she said.
Ms Christie also welcomed the reduced $2000 cap placed on apprentice fees, as recommended by TAFE to the Independent Pricing and Regulatory Tribunal, which advised the government on the new fee arrangements.
In a statement, Minister Piccoli said the new fees would mean 46,000 more students would be able to train in 2015.
The minister said fees in NSW would remain lower than maximum fees in Victoria, South Australia and Western Australia.
He said from 2015 students will pay a set fee per qualification rather than per year, and that is fairer.