We have been to all three over the past decades. Camp Hatteras runs around 100 bucks a night, KOA about the same. Ocean waves runs about 48 to 55 depending on your hook up. CH and the KOA are nice and have a lot for kids to do. OW is quieter and all the pads are cement.
Avon is 15 miles down the road and has a restaurant called the Mad Crabber. That is where we go when we don't feel like cooking ourselves. There are plenty of fish/seafood markets close to any of the three cg's where you can buy whatever you want if you want to cook yourself. There is also a Food Lion in Avon if you need groceries.
All three cg's are on the ocean side and basically a easy walk down to the beach. Depending on the severity of the winter you may have a very wide beach or a very narrow beach depending. Generally if one has a narrow beach the other two are wide.
Travel safe.