A better option would be to order from here. OWner is a good mate of a bloke who's picking up an XT660R today actually.
http://www.p3unlimited.com/master_cylinders_front.htm
On there you're looking �170 which is far better of course....but again, still a LOT of cash.
Using the company i was talking to, you could easily be looking at �100 all in for the lever including postage... It's not an MC replacement i accept.... but it's also not MC replacement money