Ross Watson, of Ross Watson Realty, said the QV figures reflected Wanganui regional values, but the city's average values were slightly lower.
A more realistic sale price was between $160,000 and $190,000, he said.
"That's predominantly the first home buyers - that's what's been driving our market, and it has been driving our market for quite some time."
It was too early to judge the effect of the new lending restrictions on those buyers.
"It's one of those things where we're going to have to sit back for a few months to see what effect, if any, it has on the real estate market."
However, the changes could have a wider reach than expected.
"It's not just first-home buyers like everyone believes, but those who are selling to trade up who might be outside of that 80 per cent criteria."
The decrease in rent prices could be indicative of a declining population, and an over-supply of motel units converted into rental properties over the past year.
Nationally, home affordability worsened again in September, according to the latest Roost home loan affordability report which highlights a growing "disconnect" between the main centres and regional New Zealand. The report measured the percentage of after-tax pay needed to service an 80 per cent mortgage on a median-priced house.
Wanganui home-loan affordability also worsened slightly from 27.7 per cent in August this year to 28.4 in September, compared with 27.4 per cent a year ago.
Even so, it is still the most affordable place in the country.
According to the latest REINZ figures, the median house price in Wanganui rose $4000 to $171,000 in the month to September.
Wanganui's average weekly pay cheque after tax for people aged 30-34 is $700.51 - the first time it has hit $700 - compared with $686.85 in September last year.
Nationally, housing affordability worsened from 56 per cent in August to 57.5 per cent in September after median prices rose $10,000 to $400,000.
