Accommodations range from high-end hotels to a few budget motels, although bear in mind that prices are higher the closer you get to the ocean. Peak season at the coast is generally from Memorial Day through Labor Day; during this three-month period, hotel prices are at their highest. The cheapest time to visit is between November and March, when the cold weather keeps the beach goers away, and many local businesses shut down.
If you want something more interesting than a hotel room, you have several options. Camping is available, although not plentiful these days. There are many bed and breakfasts in the area, particularly if you decide to stay in Beaufort, where they're practically your only option. Many visitors opt to rent vacation cottages for a week or more; they're large enough to house a family or a big group of friends, and you can often find them for fairly reasonable prices.