Property Investors Federation executive officer Andrew King said landlords - many nearing retirement age - sitting on $1.5 million to $2 million properties were choosing to sell up and cash in on the buoyant market rather than settle for rental returns on their investments.
Many of the properties are becoming family homes, reducing the number of available rentals for Auckland's 40,000-strong student population.
With University of Auckland and AUT classes set to begin in about four weeks, competition has become cut-throat for centrally located, well-priced accommodation.
A four-bedroom Bellevue Rd flat in Mt Eden with an asking rent of $650 attracted about 150 prospective tenants on Thursday and over 40 formal applications. They included a second-year bachelor of science student who has looked at 16 flats in the past fortnight.
Goode Rentals director Darryl Goode said, "I've been doing it for 15 years and this is the biggest [turnout] ever. The sad thing is there's only going to be one winner. Where are all these people going to go?"
Several people applied to rent the property before even viewing it and some turned up with their parents to make a good impression.
Many provided CV-like applications with photos and cover letters. Others offered extra cash.
"People are just saying, 'What can I do - what do we have to do to get this place?'"
Mr Goode said the shortage of inner-city student accommodation had been worsening for the last three years.
Auckland University Students' Association president Paul Smith said students were searching fruitlessly for accommodation close to the city campus.
"A lot of students are opting to stay at home and live with their parents for longer. It seems this year is tougher than last year which was tougher than the year before."
There was little the association or university could do to help.
"It's going to be tough. All you can do is start looking early, stay in the game and do your best."
A year ago, Trade Me had 4,627 Auckland rental properties listed, including 2,327 in Auckland city. Yesterday there were 3652 listed in Auckland, including 1,709 in Auckland city.
Disillusioned flat-hunter: Have everything sorted or you've got no chance
Student Taylor Green is losing faith in the Auckland rental market.
Taylor Green has looked at 16 flats in the past fortnight and lodged 12 tenancy applications, but he's still searching for somewhere to live.
The Auckland University student has been scouring Trade Me since December but is now rapidly losing faith in the Auckland rental market.
"It's really frustrating. You almost feel that as a student, especially, there's not many places willing to give you a shot." The 20-year-old science student is hunting for a four-bedroom place with three mates. Their budget is $650 "max".
The group were forced to move out of their last flat - a $495-a-week Kingsland property with mouldy carpet and holes in the ceiling - when a water main burst. Mr Green has been staying with his grandparents in Greenlane. He attended the packed Mt Eden viewing on Thursday and another in Grey Lynn last week which attracted about 150 people and had "a queue going down the street. It was like a line for ticket sales just to look at a house".
Tenants had to prove themselves to landlords and letting agents "before you're even going to get a look in", Mr Green said.
He had this advice: "You've got to start early and you've got to have everything in hand or apply before you go. You've got to have all your references sorted, a covering letter saying who you are, all your applications filled out, otherwise you don't stand a chance because there are so many other people applying all at once."
Mr Green also recommended including photos with applications to help create a good first impression.
