I fell for it with one of the 17th editions, after a few months it became a loose leaf folder.I would suggest the IET like everyone else, I am a member myself so it is a no brainer for me.
Amazon was doing an offer back in October for £55, but if you ever decide to buy from Amazon when/if they do an offer again, make sure it is "Dispatched from and sold by Amazon" to avoid fakes.