The average asking price in the South is £336,743, against £164,347 in the North.
The £172,396 price gulf is the largest Rightmove has recorded since it began its price index nine years ago, in August 2002.
The research showed a national rise of 2.8% in new sellers’ asking prices in October.
However, average asking prices in northern regions fell 0.7%, while prices in the southern regions rose 4.7%, led by Greater London.
“For the average asking price of a property in the South, you could now buy two average properties in the North and still have enough change left to buy new carpets and curtains,” director of Rightmove Miles Shipside said.
Since the start of the credit crunch in 2007, asking prices in the South have risen 5.4%, while in the North they have fallen 9.4%.
Rightmove said price decreases in the North were linked to higher unemployment figures and public sector layoffs, while more cash-rich southerners with larger deposits were able to secure low interest rates on mortgages.
