I stayed at Stocken Camping on the island of Orust for the week and it was a great choice! Agreed it is a busy campground, probably because of the high season, but I guess that goes for all accomodations in the area for this time of the year.
The prices (2008) for a caravan in high season including electra 260 kronor (approx. 43 USD / 28 EUR). A tent including 4 persons during high season will cost you 195 kronor (approx. 32 USD /21 EUR)
A nice alternative might be to rent a cabin here. The prices vary quite a bit, but the cheapest one during high season costs 750 kronor per day (123 USD / 80 EUR). Travelling outside high-season (=16 juni-10 aug) will save a lot of money on your stay.
You can make reservations for a place on the campground, but unfortunately you can't make reservations for a particular spot. It is first come, first served. So be on time during the day if you want to find a nice spot.
You can find more info about the campground and prices on their website: www.stocken.nu
The campground is a three star campground and has all facilities you can wish for. The main thing for me though is if it is clean and its location. And both were good!
My favourite part of this campground is the location. It is ideally located close to the village of Stocken, with other picturesque villages like Gullholmen Mollösund and Hällevikstrand in the area.
The campground is not 'directly' at the sea, so you don't have any sea views. But that is actually a good thing as the rocks will protect you from the cold seawinds. A nice 5 minutes walk will bring you right to the beautiful coastline! (see the photos in my must see tips).