Yes, I'm planning to be there on the 19th, my son is driving.
If it were my money I'd get the X2C and something like these (not saying get these actual items, just giving examples of what can be bought at a good price used).
Radio £40
http://www.oople.com/forums/showthread.php?t=92872
(or you can pick up a Core or Etronix 2.4GHz for around the same money)
One of these Lipos £40
http://www.oople.com/forums/showthread.php?t=92810
Motor and Speedo £60 (or £40 if you get the cheaper ESC and it can handle the motor)
http://www.oople.com/forums/showthread.php?t=92589
Just need a servo to get to the B4 set-up equivalent. A decent servo will cost around £20-40 used.
This way, you will be much more up-to-date, I know you'll spend a bit more money, but you won't be wanting to change things so quickly.
The ebay B4 looks to be a nice car but the electrics are old. The brushed motor, esc and NiMH cells are not worth much, except to get you going. I wouldn't place much value on them if I were you.