We pay 4.16 euros for a jar of Nutella, Belgians only 2.75 euros: this costs groceries in Europe

In which European country do you do the cheapest shopping? This site did its shopping in seven countries. The differences are quite big. Where a jar of Nutella costs 4.16 euros in the Netherlands, it is the cheapest in Belgium at 2.75 euros. For a bottle of sunflower oil (here: 3.69 euros) you have to be in Spain: 2.20 euros.