Don't see any problem with buying from outside the UK if it is cheaper (especially if it is cheaper after paying import duty/VAT).
For guns I prefer to buy from our local site as they offer a great back-up service and often make no charge for relaively simple repairs.
Otherwise I see no reason why I should pay say £300 or more for an item that sells for $300 in USA or Hong Kong. Even allowing for VAT, that would still only be about £230 (maybe a bit more with postage).