This may help
Vat is 17.5%
If you work out the cost of any mac in the US, add 17.5% and then
convert the currency you will see that there is still a discrepancy between the uk and US prices
I don't think its just as simple as the 17.5% VAT. HM RC will charge duty on all of these items brought into the UK/EU. From the HM RC website:
"If the goods originate from outside the EU and no duty has been paid, you need to calculate the value of the goods. There are six calculation methods prescribed. If method one is not possible, you should move on to method two, and if that fails use method three, until you arrive at a value."
Unfortunately, I couldn't locate what the exact duty percentage is for the UK. I would assume this to be in the 5-10% range (I would try and get the exact percentage, but the HM RC website asks for you to call a helpline within the UK). In any case, lets take the low end MBP.
In the US, $1199
Import into the UK incurs 5% duty = 1258.95 USD
VAT in the UK incurs 17.5% = 1479.27 USD
Mean Price Conversion to GBP (based on mean exchange rate of 1 USD = 0.656 GBP) = 970.84 GBP
Price of MBP in UK = 918 GBP
Based on this (I admit that I don't have the exact duty percentage), I think the UK MBP prices are on par with those in the US.
EDIT:
According to this:
"Customs duty - Customs duty becomes payable if the goods are over £135 in value but is waived if the amount calculated is less than £9. Customs duty is usually charged as a percentage of the value of the goods.
The amount of customs duty charged will depend on the type of goods imported and their value stated on the customs declaration CN22/CN23 (converted using the rates of exchange for the month of importation as shown on our website).
The percentage varies depending on the type of goods and their country of origin. Duty is charged on the price paid for the goods including any local sales taxes plus postage, packing and insurance costs. However, the cost of postage is excluded from the calculation for customs duty on gifts except where the sender has used the Express Mail Service (EMS) as opposed to a standard mail service.
Where the value of gifts is below £630 per consignment a flat rate of duty of 2.5 per cent will be applied, but only if it is to your advantage."
It looks like a flat rate of 2.5% for duty for gifts. I would think it would be higher for commercial items. Regardless, taking this into account:
In the US, $1199
Import into the UK incurs 2.5% duty = 1228.98 USD
VAT in the UK incurs 17.5% = 1444.05 USD
Mean Price Conversion to GBP (based on mean exchange rate of 1 USD = 0.656 GBP) = 947.30 GBP
Price of MBP in UK = 918 GBP
Still the price seems within 30 GBP of the selling price.