A mere £2k can buy you a share in a fantastically fun aircraft - a Jet Provost. Only one requirement, due to insurance reasons you must have a commercial license to join this group.
The cost per hour is more than a light single but not that different from hiring a light twin. Good for 400 Kt and +6g/-2.5g, amounts to some pretty serious fun anywhere from 3,000 feet to 30,000 feet!