The well to do scientologists I've met weren't well to do to begin with. They attribute their business success and acumen to the classes they took within scientology.
Now if we were to be skeptical that would work similarly with just about any religion or system. Some are successful, some are wildly successful, (be it in society, financially, health, prayer whatever). Meanwhile maybe the lions share are not and they drop by the wayside, yet the shining examples are constantly referred to and bring in more recruits, converts, etc. And also keep that lions share trying to do better, striving for improvement because they are obviously lacking in their faith....
Now also as with any religion, those that make it to the top of the food chain and attribute their health/success et al to the faith...they gladly support it with their dolllars....