din
To the extent of my knowledge, I believe that some misinformation has been spread here.
As Sejal has said, the way that SAC scores are moderated, it may lead to you being 'dragged' up or down, by the other members of your cohort.
Additionally, going to a select entry school will inherently provide a higher quality education, thus yield better ATAR scores.
However, contrary to the allusions of others here, you don't get some arbitrary boost (e.g. +5 aggregate score) and aren't necessarily advantaged by attending a select entry school.
Just try your best, and therefore can't be disappointed in the outcome.
