If you got that idea from
'Advanced Bookings (by 10 May) will be available at an all-in rate of £24 (including Fri & Sat camping, coach to, evening meal and band at, and coach back from Clearwell Caves), plus all on-site events. Accommodation can be upgraded to indoor bunkhouse for a further £11. A range of other permutations are also available, such as on-site camping (with use of bar, showers etc) but missing the Clearwell Caves event. '
I could be wrong but I read that to mean there are several options you can choose to pay for - including camping and clearwell - and camping without paying for Clearwell.......
Just like at Hidden Earth you pay for camping and entry but paying for the Sat evening meal is optional. If you have got that idea from somewhere else please ignore me!