Komparzon tracks 16 Car & motorbike products across the seven European Amazon marketplaces. The same item is almost never priced the same in each country: this page puts every national price side by side, converted to euros, so the gap is obvious at a glance.
Car & motorbike prices move from one country to the next for reasons that have nothing to do with the product itself: VAT rates, local stock, national promotions, competition between third-party sellers. Your Amazon account already works on all seven sites, and Amazon customer service handles returns whatever country you bought from. The only open question is where the item is cheapest — which is all this page is for.