Last year our friends paid £550 for 1 week in August in a mobile home on the beach in Port grimaud. They booked direct with the site. There are huge savings to be had booking independantly, particularly if you are a couple and don't need kids club facilities etc. Most sites have entertainment and information can be obtained from reception. Their total holiday, for 4 people, including flights and car hire for week came in at under £1000! Compare that with Eurocamp in August, which usually only includes ferry price and mobile home. If you book early enough you can get some fab ferry deals too. Look up area you want to go, then search for campsites et voila!!
Amazing family weekend with old steam engines, classic car displays, market stalls, and full catering and bar. And camping on site - Save £25 by booking in advance.