"This is the highest average price we have seen all year, and is a 17 per cent increase on the same time in 2012,'' the Harcourts report said.
"We expected a market reaction before the LVR restrictions came in, and this has been a significant one.''
In September new listings were down by 11.2 per cent on the same time last year, while sales were up by 9.8 per cent.
Harcourts CEO Hayden Duncan said the jump could be put down to the combined effect of the looming LVR introduction and the continued shortage of housing in the Auckland region.
He said the announcement that restricted lending conditions would be put in place caused both first-home buyers and investment buyers to try and snap up property before the new rules came in.
"First time buyers who can't scratch together a 20 per cent deposit will be looking for rental properties, and that's moving the investment market,'' Mr Duncan said.
Barfoot and Thompson's data showed an average price rise of 1.6 per cent or $10,000, with median prices up 6.9 per cent from the previous month. Sales were down 7.9 per cent from August.
However, its managing director Peter Thompson said the figures did not indicate a surge in buying prompted by the LVR rules.
"Month by month variations in sales numbers are common, and if the Reserve Bank's new regime was to have had an impact, I would have expected more rather than less sales in September as buyers sought to get in ahead of the new deposit requirements,'' he said.
Mr Thompson said it could be between three and six months before it would be possible to judge whether the mortgage changes will have any medium term impact on prices or sales turnover.
However, both agree that September saw the highest average prices for the year.
That's consistent with Realeastate.co.nz's NZ Property Report earlier this week, which also showed September's national mean asking price reached a record high.
In early September the credit agency Veda reported a spike in mortgage checks for under-28 years olds, which it said showed first home buyers were rushing to beat the October 1 clampdown on low deposit lending.
See an opinion piece by Reserve Bank Governor Graeme Wheeler explaining the purpose of the restrictions here.