Nigel - you seem to be willfully ignoring the real world as it is impacting on UK consumers...

I studied and passed Economics A level 40 years ago, continued the subject during the first year of my degree,
and even if I could now be bothered refamiliarising myself with all the grand theories and mechanisms...

It still would not change my educated opinion about Rip Off Britain...

Even petty things like DVDs/Blu-rays & CDs...
The USA and other foreign markets tend get far more value enhancing extra features included,
than the UK versions provide...

These are rarely exported to us due to global licensing restrictions,
and even when they are, the import shops charge extortionate prices.

Then there are the foreign CD/Movie titles that never even get any kind of release in the UK...

That's why canny consumers try to buy direct from USA / Japanese / etc shops at their local prices,
and though it is still expensive and we still get caught by customs duty, VAT, etc..
It will still usually work out cheaper than the UK rip off prices...!!!