Why do NIKE shoes cost twice as much in Prague than in the USA?

I study retail prices of sport goods for a particular multinational producer across European countries and in the USA to examine behaviour of the law of one price. Although average prices across all goods in the sample differ only slightly across most of the countries, I find significant price differences for individual goods for almost each country pair, including a group of the states that are generally considered as relatively integrated. The conducted analysis has not confirmed that these differences are caused primarily by various distribution costs. The computed relative prices across products vary significantly once compared internationally even within a group of similar goods of which distribution costs should be the same. The price variation, which prevails even when costs are excluded, points to the existence of strategic pricing and lagging arbitrage.