While average rent per bedroom is $125-$130 and the average house price $420,000, rents of $155 to $170 are not uncommon for top properties, with plenty of property sales of $500,000-plus.
Colliers International campus investor broker Matt Morton said purpose-built studio units were now ''commonly'' rented out ''for upwards of $300 per week''.
''The compelling supply and demand trends operating in the student accommodation market mean student flats here are recognised nationwide and overseas as an anti-cyclical investment,'' he said.
The number of foreign-owned flats had tripled from 2% in 2012 to 8% in 2013, while North Island ownership was around 11%-12% for both years, the Colliers' research report said.
''A large numbers of buyers are now coming from outside Dunedin, including a steady number from the North Island and increasingly, from offshore,'' Mr Morton said.
Median yields for landlords were about 7%, with occupancy rates highest in flats closest to the university.
The housing stock around there was tightly held - representing about 9000 beds.
Mr Morton noted that university enrolments had declined since 2011 and students were demanding increasingly higher grades of accommodation, meaning landlords should not be complacent.
However, the first year enrolments were ''stable'' and North Island and foreign student numbers had either increased or been stable during that period, he said.
''It's essential that student flats provide value for money, as the students do shop around and increasingly demand quality accommodation for their money,'' he said.
Landlords had to have kept up their maintenance and presentation ''at the very least'', if they wanted to raise rents by even $5 per room.
Otago Property Investors Association president Wendy Bowman said Christchurch and Auckland investors were increasingly coming to Dunedin, because of rental yields of in their hometowns of just 3%-5%, compared with Dunedin's 6%-7%.
Investors Association membership was 600, with only a small percentage owning university properties but those who did had 10, 15 or 20 properties in their portfolios, she said.
''Dealing with students is not for some but others see guaranteed income and are prepared to listen to what they [students] require,'' she said of insulation, Wi-Fi, security and technology adaptability.
''Students are wanting higher quality flats and to get value for their money.''
While the average university flat price was more than $400,000, ''entry level'' investments could be purchased for about $300,000, but Ms Bowman cautioned they would likely need a further cash injection and a lot of work.
She said on an annual basis a small number of flats were left untenanted, likely because of lack of sun or insulation, access or small rooms, but that outcome was entirely linked to university and polytechnic enrolments for the year.
She said many new, mainly four to five-bedroom houses were under development, which would ''be putting pressure on the older housing [stock]''.
Mr Morton said the university expected 1.5% annual growth in student numbers over the next 20 years, which equated to an extra 200-250 bedrooms being needed every year.
About 63% of students lived in shared flats, he said.
In what appears to be an off-setting exercise, Mr Morton said while out-of-town and foreign student numbers were either stable or rising, the number of students originally from Dunedin had declined ''massively'', from about 5200 in 2011, to 3400 in 2013.
He said there was no evidence of any emerging trend toward construction of larger developments in the area.
But there had been a small number of development sales over $2 million, which contained several flats, each with four to five bedrooms.
