Just got off the phone with Dave Walton at Bruntingthorpe and it is a weeeeeee bit expensive for 20-25 people. He only has one weekend date available and that is the 1st of June. We would get exclusive use of the site for this day and we would get all the timings we want including a top speed run and a timed handling track for testing suspension etc. All the timing kit would be provided.
He says he SHOULD be able to get it down to £4k for the day - so working that out it would be £200 a head if we had 20 people turn up.
The more we get - the lower the price per head would be. He says he could accomodate up to 40-50 people on the day. This would mean that it would bring the price down to between £80 and £100 a head although I am a little retisent about achieving those kind of numbers.
One proviso that he asked for was road legal exhausts - so stripping out and getting a through exhaust for the day would be a no-no!
The only other alternative isn't much cheaper, but would mean a Friday deal from 12noon to around 6pm - again with exclusive use of the site. This would be around £3.5k.
Bare in mind that I've haggled hard and the original figure that I was quoted was £7.5 k for the 1st June

I personally could afford the £200, although for £320 I could get myself a Performance box from Racelogic and do all the testing myself (but where's the fun in that!) and might get the box regardless

£80 to £100 is a much more reasonable figure and does mean that you would get the performance figures, a handling stage and a great day out for the forum.
If we want the 1st of June we would have to move quickly as it is only March and all the other dates are already full!
If this falls through I would look at somewhere else (but not quite as central in England) - so don't worry too much at this point!
Let me know what you think about the prices, date etc. Cheers.