"Our selling costs in Europe and Asia are higher than in the US because of the size of US market and retailers (economies of scale). Furthermore, the US market is by far the most price competitive in the world. These factors combined mean that we have for years priced our products higher in eg Europe than the US. In recent years, the difference has been increased due to the weakening US dollar but we have consciously decided not to let this (hopefully short term) weakening of the dollar hurt the US consumer. And in order to stay profitable as a company, we cannot decrease our European prices especially seen in the light of increasing cost pressure on oil, labor etc. Finally, final pricing in the market place is obviously determined by retailers, which is something we cannot and will not influence."
Don't forget VAT and other taxes. US taxes are significantly lower.
Source ===> Why the US has the lowest LEGO prices
Also taxes.