@Shelbii, it can get expensive because there are usually regular dues to pay. Sometimes they charge for events as well.
@Urban Homestead, whether it's worth it will really depend on your specific CoC. I've been a member for years because they do a lot to support local businesses and it's a great networking opportunity. I get a lot of bang for my buck! Unfortunately, some other CoCs do little more than take your money. Maybe you could check around to see how others feel about their membership in your area.