The regs gets an amendment and a new Yellow book, Can only mean new regs book and a new course with more expense. Wish I were a bloody painter!
New books Yes, Amendments don't result in having to do new courses, fortunately.. But even then its what £90 for a new regs book and GN3..
Amendments to regs DO result in courses, your area engineer will ask if you have latest amendment (My last amendment was taken at ETS in Brum which was a one day update course with C+G 2382-12)
We've had amendments which haven't involved courses, it's changes of regulations editions which result in courses, eg 15th. to 16th. 16th. to 17th. etc.
As I said, and Seneca has expanded on amendments to reg's don't involve going on a course, however after hmm 4 amendments the reg's are re-written to the next edition which will then usually require some sort of course.. You can just print the amended pages of the IEE website and stick in your existing reg's book rather then buy the new one..