I looked into this, and discovered their USA v. European map pricing scam.
I haven't the faintest about the product you chaps are talking about, but as regards the quote above, more than a "scam" as such by the company selling this products, it likely is related to the respective licensing costs for US and European data. I wouldn't be at all surprised if the U.S. charts were freely or very cheaply available in electronic version. As for the EU counterpart....
Just speculation on my part, but I bet for once I'm not too far wrong.