Go down to your local gliding club, and ask about a the cost of a lesson in a two-seater glider. You may find that it is (and I quote) the most fun that you can have with your trousers on.
If I was back in the Midlands, I'd be back at Husbands Bosworth airfield. Trial lessons are about seventy quid and there's an evening programme in the summer. Getting your pilot's certificate will cost hundreds (but not thousands) of pounds, and is cheaper if you do the 1-week intensive course, bunking down at their clubhouse. Wish I had the time!
That would be Cambridge Gliding Club, who I've just seen advertising trial lessons for £60 in one of the local freesheets. (Honestly, what's the point of delivering a newspaper with the weekend's television on Sunday afternoon?)