They had caravans on the website for £700 -£780 but when I called they had some very inexpensive older ones (not further from the sea and not with less amenities) than the newer ones - just a bit scruffier.
So I got a week in August for £500
Anyone been there? It looks like a lovely bit of Dorset - you can walk down the steep cliffs to the Durdle Door beach from the caravan site.