We try to go off season as this is the best time for pricing as well as it is not too crowded. They are the only campground left on the island that is ocean front with a 5 star rating and I guess they feel it is ok for them to charge exorbitant prices. That being said, they are still cheaper than a cottage ocean front.
If you do not care about being ocean front, you may want to try
this campground. They do have waterfront sites with some pull in sites. They are a little remote but it is a wonderful campground.