Seeki.eu lists 2,500+ properties for sale and 80+ to rent in Groningen.
The median asking price is €375,000, or €3,557 per m² on a typical 110 m², across sale listings that publish both a price and a floor area.
On the rental side, the median asking rent for an apartment is €1,135 a month, across apartment rentals that publish both a price and a floor area.