Do you want business or econ ? They are very different. Two of the three don’t have business although NU has a program of sorts
If you want merit, this isn’t the group to apply with it not possible at NU.
Depending on how impactful your service is, I’d think UND is your best odds. I think the other two are less likely.
That said, you have a great profile so I lean no but you never know.
But you need to pick your major. That is far more important than the school name in my opinion. And business and Econ are not similar. And then pick schools based on the major
What type of AP scores have you gotten ? What’s the highest level of calc ?
You are strong applicant in the grand scheme of things but TBH NU, UChicago, and ND are all major reaches for the even the best applicants. Your ACT score is on the low side for these schools but you are lucky that you have ND legacy status and it does give you the best shot at that school.
Regarding budget/cost constraint, you state that "merit would be nice” but these schools don’t typically give merit. have you run the NPC or are your parents willing to go full pay (~$90k/year for 4 years)? i am assuming so by your response, but it was not clear from your post.
i hope you have some target and likely (safety) schools on your list as it is entirely possible you don’t get into any of these three schools. Perhaps a UIUC as you seem to like to stay close to home in IL?
Based on your stats and EC’s, I think you have a very good chance at both. My DS was accepted to both ND and Northwestern last cycle with similar EC’s. He also lettered in two varsity sports.