Depending on what you are trying to do, you should not consider getting fewer than 25,000 annual points. That will get you into many of their top resorts every other year. You can also buy smaller interests and combine up to 3 of them into one membership.
BUT regardless of what you might have heard, RHC is not for everyone. The resorts are great, but they are probably the most administratively screwed up organization I have ever encountered. You will occasionally have to pay your annual fees twice, regardless of what documentation you might have. When you talk to their counselors on the phone, even if you get one who speaks English well, they often will say whatever they need to in order to get you off the phone as quickly as possible. And you can never rely on what they tell you, because the next rep will tell you something exactly opposite.
That said, I have used RHC to book directly -- or trade into -- many great places. This summer, I am using my membership to go to the Hotel Napoleon, just steps from the Arc de Triomphe. Last year, I used to to go to Madrid over spring break. The year before I went to New York City in May, and the year before that, I went both to New York in Autumn and Madrid in spring. One year, I traded it via RCI for Amsterdam.
So, expect headaches and if you are the type of person whose blood pressure goes up when faced with lies and incompetence from your timeshare organization, you need to pass on RHC. But if you are fairly laid back, willing to take the administrative difficulties in stride, then RHC will get you to some amazing places.