Originally Posted by Dave Noble
UK Duty Free has some similar concepts. If you were to bring in, say, a laptop computer worth GBP1000, you would be charged VAT on the whole GBP1000 rather than the excess over the GBP450 (iirc) allowance since you cannot claim allowance on any item which in itself exceeds the allowance.
Though I'd bet that there aren't very many 3 litre bottles of alcoholic drink brought through Customs.