Hi
NatanshaWhile the official Guide books are really great stuff, since you can find all those questions here on the GMAT club so I don't recommend that you purchase them
Instead spend time understanding how to filter questions from OG here on this forum.
For DI, there is a lot of bad material pouring in than good material (just like in Verbal). Therefore, it's important that you know which questions and from which source should you practice questions.
Official sources are always best but are those questions enough? I am not so sure. I think a lot of practice is a good idea to be confident of getting good score. That's why I share the collection of very good questions with my students who come to seek help in these section.
All i can tell you here is that All good questions are on this forum. Just finding them isn't a straight line method.

Happy to help!

Natansha
Hi everyone,
Would really like to know if it's necessary to purchase the Official Guide Question Bank & DI Review Question Bank for DI Practice or just the ques available on the forum would be enough?
Are all official questions covered in the GMATClub forum for DI as there are very ques on certain topics such as MSR?