Lots of great tracks in the UK some of the smaller ones offer great value, Derby, Bllyton park to name a few, ok there not massive but you can still come off shattered.
I tend to skip the last session or just go out and take it very easy, you will be surprised how tiring it is. (in a absolutely awesome way)
(if i was mega rich i would hire it out for day and get everyone ****ed, and give them a CB250 for races)