There are three pricing structures.  

1. One accommodation unit with 2 adults - £20 per pitch, up to 4 adults can be added to this pitch

2. One accommodation unit with up to 2 adults and 2 children - £30 per night, up to 2 adults can be added to this pitch

3. One accommodation unit unit with up to 2 adults and 4 children - £35 per night