This is a simple question: why does a membership cost $200? Is it just because the HQ has to pay the bills? Or is it for something else? This isn't Scientology, so I imagine the reason must be good.

The simple answer is:

To weed out those who won't even pony up such a small amount for something they claim to support.

The more detailed answer is:

Because it's a LIFETIME membership and will have to cover all administration costs regarding your file for the rest of your life/membership. I know the kiddies don't believe it, but there are distinct advantages to being a member, at least if you put any further effort into it, and to expect them to do all this for free is ludicrous.

But, you're not required to join. If $200 is more worth than Satanism has contributed to your life, then I not only suggest you save your money, I actively discourage you from joining.