Well, one point: Pretty much everything costs more in Europe than America. Food, clothing, housing, etc. If european prices were charged for Lego in America I doubt people would touch it, because it would seem unreasonable compared to everything around it.
Also when we say Europe 60%, America 40% (for ease) you have to consider the costs/logistics involved in each. The 40% is contained in one country and involves massive shipments to TRUS, Target, WalMart etc. The Europe quota is shipped to many individual retailers, in many different markets, at different prices, in a very diverse (marketing wise) landscape...
2 Bricks.
God Bless,
Nathan