We stopped on a site in Lake district as daughter wanted us to, 2005? £25 ish, bloody rip off, we don't do 'sites', as cannot justify wasting the money
to just park up for the night, as we wouldn't use their facilities, and don't like the rules or kids for that matter, that you get on sites. We do go to meets where they sometimes charge a small amount, or ask for donations to charity, but these are not registered camp sites. Much prefer wilding away from the hustle and bustle If I had young kids it would be different as the sites give them something to do.
In France etc, the Aires are fine they are generally very cheap, and very well looked after, so don't have a problem paying for their facilities, unlike rip off Britain.