Almost one in three first year students at UK universities say their courses are not good value, suggests a study.
Dissatisfaction grew when fees rose for English students, say researchers for consumer watchdog Which? and the Higher Education Policy Institute (Hepi).
The report highlights big variations in teaching time with students at some universities getting twice as much as those doing the same subject elsewhere.
The issue of relative standards needs urgent investigation, urges the report.
The raising of fees paid by students from England to a maximum of £9,000 a year from last autumn has "put universities under increasing pressure to deliver, and be seen to deliver, value for money", say the authors.
Of 17,000 students polled across the UK earlier this year 29% said their courses were not good value for money, compared with only 16% the last time the study was carried out in 2006 when fees were just over £1,000 a year.
Students who received less contact time with tutors in the form of lectures, seminars and tutorials were three times more likely to say they did not think their course was value for money, according to the report.
Many students were working harder than in previous years with the amount of private study they said they were putting in per week rising from 12 hours 48 minutes in 2006 to 14 hours and eight minutes in 2013.
Some 65% of students said they gained from being taught in small groups of up to five students.
A third (32%) said they might have chosen a different course had they known more about the academic experience, with a fifth (21%) saying that information from universities was vague and almost one in 10 (9%) that it was misleading.
"Our surveys consistently show the large variation between those universities that require the most and the least workload in any one subject and raises again the question about the comparability of standards between these institutions," said Bahram Bekhradnia of Hepi.
"It is unlikely that students, studying for on average less than half the time studied by other students on the same subject, will achieve the same outcomes."
Which? executive director Richard Lloyd added: "With an increasingly competitive higher education sector, and soaring tuition fees, it has never been more important for prospective students to get as much information as possible to help them make the right choice.
"There must be an investigation into the huge variations in the academic experience that we have revealed, and more transparency to ensure students can get the information they need."
A spokesman for the Department of Business Innovation and Skills agreed that "people must be able to make informed decisions about what and where to study.
"Institutions should explain to prospective students how their course will be delivered in order to help them make the right decisions.''
Rachel Wenstone of the National Union of Students said government changes encouraged "students to think more like consumers" but denied them "any way of holding their institution to account" if they were dissatisfied.
"The government needs to undo its shambolic changes to higher education and find a better way for graduates to contribute towards the education system, halting the 'marketisation' of universities that is of no benefit to students or society."
Nicola Dandridge of Universities UK said increased fees meant that students were demanding more from their universities but she insisted that overall satisfaction levels remained high.
"It is misleading to make a crude assumption that time spent in lectures and seminars can be equated with university course quality. UK university education places an important focus on supporting independent study which will vary from course to course and between individual institutions."
'Bang for buck'
"Tuition fees also pay for far more than contact time. They cover all manner of services including student support facilities, employment advice and training, library services and clubs.
"It is essential that students fully understand what university will offer them, and universities are continuing to work hard to provide prospective students with more information about what they can expect from their courses."
Sally Hunt of the University and College Union said: "It is perhaps not surprising that some students and their parents expect more bang for their increased buck, following the rise in university fees.
"Frustratingly, despite the hike in fees, universities are not any better off after the government slashed state support for higher education."