The Watch Tower has never revealed to the rank and file JW the actual cost of the literature, CDs, and Video tapes. But I can tell you from my experience in retail bookselling that when the publisher's suggested retail price for a book is $20.00, the retailer paid $10 or less for the book. The cost of goods for most large retail book chains is probably even less, around 40-45%.
Since the Watch Tower both prints and publishes their books, their actual costs should be even less. And when you factor in the large print runs of Watch Tower literature, costs are further reduced.
Back in the 1960s the Watch Tower was charging the JWs 3 cents for the magazines and 45 cents for the bound books. The pioneers were charged 1 cent for magazines and 10 cents for the bound books. These rates for pioneers gives one an idea of what the actual cost to the Watch Tower was for these items at that time. I would guess that the Watch Tower even made a profit on pioneer sales.
Sincerely,
Athanasius