I was 15 in '86, my individual prices might be a bit off, but could definitely do it with a fiver and get change. Turning 16 doubled up the train fare and entrance fee, but I could do it still for a fiver if I bunked the train.
When I was 15, I could do the day out on a fiver and have change, train fare from Crawley £1.50 half fare, Junior entrance fee £1.50, Programme £0.50, box of ten fags £0.80, chips from Sing Lee, £0.50.
I miss terraces, crowd surges, slide tackles, slam door trains, and the occassional BR donated...