I'm not sure about current prices in UK for Macs but it used to be insanely expensive there. I'm in Paris right now and you would pay the exact same price for a MBP here as you would in the States...except here it's 2200 euro and in the US it's $2200. That's $700 savings!!! Plus, if you get the student discount, it's a no-brainer.
And if you like portability, I agree with jeremy h - the 17" MBP sounds great.