Edmund is correct about MAP, the 645Z is around $6000 with a passport.
B&H offer a worldwide delivery service, all taxes and import duties of the destination country paid & guaranteed.
MAP price is $6,000
B&H price is $8,499
Based on the B&H price, taxes and delivery, in addition to the $8,499 would be
UK / France $1,827
Italy - $2,004
If based on the MAP price of $6,000 they would in all likelihood be less, particularly as B&H most probably include a 10% 'safety margin'. UPS Worldwide, 3-5 day delivery is $137 (included in the b&H price).
So, cost of a 645z EU delivered , is probably $7,500 - $8,000 all duties and taxes paid. A saving of $2,500-$3,000. USA about $1,000 less.
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On a cam as 'substantial' as the 645z, don't think it's even worth considering the other options mentioned so far.
Suspect that Pentax may well be viewing this as a 'pilot scheme', waiting to see what the take-up factor is. They've made no secret of their preference to centralise their ops (in Japan) and yes, you need to send the cam back to Japan if you need service or repair - but then you've got to do the same with Leica - so it's not necessarily a deal breaker.
Add to the above that the Yen has devalued by almost 22% since August, if the demand picks up it's a 'win-win' situation . 'Win' because boxes shipped&sold increase and 'win' because Yen revenue will be up - cross elasticity of demand at work.