Many of the Groundschools now sell their notes to anyone. (Eg Oxford, GTS (Bournemouth).
I buy and read them to while away the long Birmingham Winter Nights. Prices vary from £30.00 to £60.00 per manual. Most of the providers will give you a discount when you eventually strart the course if you have purchased the manuals from them in advance.
The purchase you really want to make us BGS's CD which I believe includes all of their notes and multimedia (£500).
I have pacos book and it is readable and useful and regular updates and improvements are all available.