The towns of Castlerea and Ballyhaunis had the cheapest median house prices in the year up to May.
New figures from the CSO show that residential property prices increased by 5.5% nationally in the 12 months to May - with a 6.2% jump in the price of houses and apartments outside Dublin, and a rise of almost 5% in the capital city.
Blackrock in Dublin was the most expensive area, with houses selling for a median price of €625,000.
The five most expensive Eircode areas in which to buy a property were all in Dublin, while at the other end of the scale, Castlerea in Co Roscommon and Clones in Co Monaghan were cheapest.
The median house price in Castlerea was €86,000, followed by Ballyhaunis on €91,750.