Scientology does not require you pay any money to be a Scientologist. However, books and courses do cost money. The Catholic church has been around much longer than the Church of Scientology, and operating the church does cost money. From purchasing buildings (you can't have a church losing it's lease) to paying staff members, campaigning for human rights to paying the water bill, all these things cost money. Scientologists tend to be very generous, especially, when their money goes toward helping others. So, the "expense" of being a Scientologist is not a consideration for Scientologists, but is a popular point of attack for anti-Scientologists. Below is a link to an independent study by Frank Flinn. It should be notes that Scientology goes to great lengths and expense or their world-wide anti-drug campaigns, their literacy campaigns and their human rights campaigns. The insignificant amount you may pay to buy a copy of Dianetics, or couple hundred you spend for introductory auditing adds up to greatly impact lives the world over.
The "Cult of Greed" statement very much false. The Internal Revenue Service agrees that the Church of Scientology is not a for-profit organization.
Frank Flinn Report