The average consumer (which accounts for the majority), is not going to go hunting for PC parts. They are just gonna buy what the OEMs shove in their face. Building systems is generally reserved for enthusiasts.
You just don't seem to get it, the only way AMD wouldn't charge ridiculous amounts of money is if the EU went after them.
if prices skyrocketed on prebuilt OEM systems people would just buy more custom built jobs at local shops.
and OEM wouldn't endup paying more for their AMD chips in EU because it would still be cheaper to just order more for the US plants( if they even have plants/assembly shops over there) and ship the chips/parts to the EU, again your logic fails to function as long as there are 2 companies.
If the price on AMD or INTEL parts are drastically cheaper in one country then in others, people will just order their stuff online and wait for shipping, OEM's on the other hand ALREADY HAVE THEIR CONTRACTS FOR PARTS, if they have to they can just ship the supplies or whole systems over, Normal people wouldnt endup knowing the difference, geeks would because if they wanted intel they would have to import the parts themselves or buy from a specialty shop that imports them(making the cost higher)
good example is the FiiO headphone amps, You can get the e3 for under 7bucks on DX and the e5 is like 17bucks on DX, if you buy them in the states from most retailers you pay 30-80bucks for the same thing!!!( i found 3 places that sold the e5 ALONE for 80bucks!!!) its crazy, BUT with a little searching you can find DX and order them cheap as hell, sure you may have to wait a few weeks if they arent in stock, but hey, its still cheaper($7/$17 is the shipped price) enough cheaper that its worth the wait, You cant tell me geeks wouldnt do the same if Intel or AMD chips where to price inflate the same way as teh FiiO amps do when they cross the big puddle.