I really liked http://www.thequietsite.co.uk/ – I think it cost me £8 a night. They have all kinds of pitches and static caravans too ( if thats easier.
It’s fantastic place with basic, but good amenities. It has a little old pub lodge thing on site with a fantastic old open fire, it has a little dairy and camping bits shop on site too…
It’s just far enough out of the way to be utterly quiet and no street lights, so the stars are amazing and the milky way is clearly visible, the longer you look the more stars become visible.
It’s very near a local town with supermarkets and lots of touristy stuff near by and nice restaurants/pubs.