Discussion with DH, as everything seems to be listed as an extra now!
Campsite we were on last week was £30per night, including two adults, 1 tent, 1 car. Children were £4 extra each.
On the price list there were the costs for EHU, dogs, extra cars, extra tents, extra people, gazebos...
We were paying for the location and the fact it was high season. Other pitches were as much as £75!
Site we are going in a few weeks is £45 for 4 of us, but includes swimming pool and entertainment.