As @mom2collegekids pointed out, @IlliniDad18, you need more than a high single-sitting ACT/SAT score. You ALSO need a GPA of 3.5+ (freshman through junior year).
In another thread, we speculated that approximately 52% of students (3,389 out of 6,428) are receiving some form of non-need-based aid, the bulk of which we were assuming is the automatic “merit” aid:
http://talk.collegeconfidential.com/discussion/comment/19684580/#Comment_19684580
http://talk.collegeconfidential.com/discussion/comment/19686282/#Comment_19686282
I’m not sure what percentage of the other “half” is out-of-state, but it’s not insignificant. It’s probably not well-represented here on CC (because most of us discovered UA while looking for affordable alternatives for our kids), but I’ve met lots of families who chose UA full pay because it’s not much more expensive than their in-state options (which their kid may or may not have been able to gain admission to) and/or it’s far less expensive than full pay at a private when the student isn’t competitive for merit aid.