Hopkins said an agent told her the landlord had fixed some plumbing and was planning to put some carpet in one of the rooms.
"The thing is if I had got the property at $280, there's no way [the landlord] would have been able to put it up $70. He would have had to fix up the leaking by law."
Hopkins said living the way she and her family were in a cramped three-bedroom house was becoming untenable.
"[It's] terrible," she said. "We're all still together which is a blessing. [But] it comes to a point where everybody gets on everybody's nerves.
"I love my family, they love us, but I think it's just too long now. I think they need their break. There's three families living in there, even though they're all my children, there's three lots of families there."
The manager of property management at Ray White Wanganui, Fiona Callister, said the price increase on the Karaka St house was indicative of Whanganui's tight rental market.
"It's just how it is at the moment with the market ... it's just been increasing. [It's] probably a good thing that she said she couldn't afford it rather than it turns out she couldn't afford it," Callister said.
"That's just how it is at the moment, unfortunately. We try to do our best to help people get into properties but it's just the market at the moment, that's what the problem is really.
"We have increased rents and that's just been all around. It's not in one property ... a lot of the properties have been increased in rent."
She said compliance costs for landlords were one of the main drivers for rents increasing.
Callister said Ray White wasn't adding the now illegal letting fees into the recent rent increases.
