at £30 a night its far too expensive. we go to a lot of the shows and always stay at kingsbury water park. its only 8 miles away a 15 min easy drive, plenty of space and great walks round the local lakes, plus the last time we were there we found a miniture steam railway with great rides round the park just a 10 min walk from the site.
cant understand people whom pay the expensive on site camping fees to stay on a tarmac carpark and porta loo facilities plus be off site early or else. at least at kingsbury as long as there is availability the staff are very helpfull and can be flexible with a late departure which can come in handy if you need to return to the nec the following day if you need to return anything, thats happened to me twice now lol.
cheers
John