Thats because you're including around 500 Euros in tax for the German price and 0 for the American price.
Tax cant be included in a comparison between prices as it has nothing to do with Apple and they don't see a penny of it.
I'm not disagreeing but those in countries outside the USA see the tax less pricing the USA has and thinks that the US buyers are getting a bargain. The reality is as you say it's just not including tax.