MagSeal is right, and Bell takes it very seriously as well. It can be very dangerous to refer to any controlled document that isn't properly maintained.
The cost of the manuals is not so much a money-grab by the manufacturers, but the astronimical cost of actually producing them (not the printing, but the controls and distribution costs).
Having said that, using an old RFM for reference and study probably isn't that bad, but you should try to get a current version if at all possible. The 206 series isn't likely to see many surprises, but some of the newer types can see big changes in the first few years.