Whangarei couple Cameron and Shanelle Kennedy and their two children moved out of a two-bedroom unit in Raumanga about two months ago. They moved in with her mother on Third Ave because they had nowhere to go.
All four sleep in one bed.
"I've been actively looking for a house on Trade Me every hour. We can pay up to $350 but with that amount we either pay rent or feed the family," she said.
"Most landlords want $2500 bond which we'll have to sell our soul to pay. There's no regulation that governs what sort of rental properties people should get under different price ranges."
Mr Kennedy works as a security officer while his wife does casual work.
Nurse Reijish John is paying $200 for a single-bedroom cottage in Paihia but his wife's work in Kerikeri means his family will have to move closer to her workplace.
That will mean forking out between $400 and $500 a week.
"Last week one of my colleagues showed me a property for which she is paying $310 per week but when the landlord listed it on Trade Me, all of a sudden the price increased to $395."
Mother of three boys Shontel Thomas said she now has two weeks to find another property after the rental was sold and she was given notice to move out.
Another mother, Toni Russ, said she may have to move into a caravan with her four children when the lease on a farm her rental house is on expires in four months.
Trade Me figures show the median weekly rent in Northland rose from $282.50 in September 2011 to $395 last month.
The weekly rent for medium houses rose the most of all property types, from $310 to $420.
Head of Trade Me property Nigel Jeffries said Northland was one of the "halo regions" where the property and rental markets have been extremely strong for the past five years
He said the median weekly rent in Northland has made large jumps in the past five years as the Auckland property market boomed and many investors and tenants made the move to neighbouring regions.
Real estate experts in Northland said the current trend was to be expected, as the rental market was more or less stable in recent months.
Paul Beazley of LJ Hooker Whangarei said the figures were accurate enough for Northland's current market.
"There is demand [for rental properties], and very few vacancies, but the supply and demand is probably in a mutual state."
Renee Wilkinson of Harcourts Whangarei said demand slightly outweighed supply.
"Although we had over a thousand inquiries in the last week, we had 40 to 70 people show up at viewings."
Both agents noted Northland had experienced an increase in population in recent times, with people coming in from all over New Zealand. This had partly contributed to the rise of demand for rental properties.