Hi, the official practice tests are even more scarce resources, so I would not say to buy them for "practice" purpose. Most likely you'll need them anyway, either to gauge your progress at certain milestones during your study, or to build stamina, try out section order, and/or practice timing strategy towards your test date.
When I said "in short supply", I was referring to around 550 official DI questions in the Main OG and OG DI Review Guide combined. More specifically, it's the non-DS questions that are in limited number. (You can get a lot of DS questions from past OG, GMAT Prep, etc.). Excluding DS, there are only around 300 official OG questions available for G&T, MSR and TPA.
If you exhaust the 300 or so question, you will have to resort to 3rd-party sources in the forum. In addition,
GMAT Club Test sectionals (I think 10 sections?) is a good alternative. Also there is an "Official Practice Questions - DI" bundle for sale on mba.com, but it's quite expensive on a per-question basis ($29.99 for ~100 questions).
adhin31
Hey !! Quick question - would you recommend buying offical practise tests towards the end of the preparation for practicing quality DI questions ?