You can see the current price in Sterling on the Basic4ppc purchase screen by choosing "United Kingdom Pounds" as the currency. You can actually pay in any currency that your payment method supports if you think you can do a bit of arbitrage and make it work for you
. If your address is in the UK 17.5% VAT will be added to the price you see on the first screen when you see the final amount to be debited on the next screen. The total is what will be debited from your payment method which may or may not have further charges.