Weaselz and myself did level one early this year at Silverstone. I think it was around 320 odd quid and I personally got a lot out of it. Don't be lured into thinking it's just a track thing - everything the teach is you applicable on the road as well. In fact, most of the riders on the level1 course were track virgins on a whole variety of bikes.
Here is the original thread:
http://forums.sv650.org/showthread.php?t=89390&page=4
Thanks
Luke