Now this is a very interesting discussion...
I guess european retail prices also have a lot to do with the relative small markets you have here compared to the US and the varying tax rates. I travel a lot all over Europe, and most prices are lowest in Germany
All over the Euro zone prices are comparatively higher, depending on the taxes of the respective countries.
For GB, Scandinavia and most eastern states you also have the problem of varying currency rates and import tolls, although I don't understand why I found a PB 602 in the Ukraine tagged at ~ 250€ when it's sold for little under 200 in Germany

That said, there also is a phenomenon I call localism. Whenever I talk to friends about special offers or bargains, they
never look out of their local markets. They are quite astounded when I'm telling them about things I ordered from varios countries all over Europe, which were much cheaper than here despite shipping costs and customs. A country like the US, where distances greater 500 miles are quite common and at your destination you have the same prices than at home (and the same shipping costs to NY from LA or NJ) gives customers a very different attitude towards local traders than in old Europe.
And a merchant would be bad at his job, if he wouldn't try to pry the max price out of his customers, regardless where he or they live