Guy
We stayed as several small sites in Holland this year, they are known as Mini Camping. They are usually in rural areas on outskirts of cities on small holdings or small farms.They are a bit more sophisticated than a CL with washroom,showers and electricity.They usually take 10 to 15 vans and some have hard standings.The most I paid per night including electricity was 15 euros.Sites were all clean and well cared for and some had small shops attached to purchase local produce.If you look in the Caravan Club European Sites book vol 2 you will find many in the Netherlands section.
Clive S