Following on from Broomsticks good advice,
Wait and see how you go with the notes supplied by your course provider.
If you feel you could do with some 'extra' then selectively purchase one volume on a subject.
You'll either benefit from a slightly different approach to explaining parts you find tricky, or realise that your course providers notes are quite sufficient. Probably somewhere in the middle.
A bit better than throwing a load of money at the whole set for an unknown benefit.
Also its unclear from your post whether you have embarked on the ATPL course yet, and some time spent on the search engine learning about what people have said about the different ATPL course providers will be well spent.
Whichever course you are on, there will be a lot of material to get through - will you have the time to read the same things twice, explained through different styles?
Regards,
Laurie.