Will a school with a majority of in-state students be more likely to give OOS students more money?
No. Less likely. Public universities are largely funded by their state tax payers, and their primary mission is to educate the students from their state. Most state universities give no need based aid, and a lot more merit is awarded in state vs OOS. I don’t know of any public school that gives more money to OOS students.
I guess the one “exception” would be the few public schools that say they will meet need for OOS students (UVA, UNC). Since OOS tuition is higher, they are providing more aid to meet the student’s need. But they are highly competitive for OOS students.
Okay, another exception. Some regional private liberal arts colleges may give a bit more merit aid to “geographically diverse” students.
Haha I probably don’t fall under that “geographically diverse” category. Thanks
Well… you might be for someplace. If you live in NY, look at Willamette in Oregon. If you live in LA, look to Dickinson in PA or Kalamazoo in Michigan. Everyone is geographically diverse someplace. 
If you apply to PRIVATE colleges 400+ miles from home and they’re not Top 25, you offer geographical diversity. That may result in preferential admissions and packaging (ie., more aid).
Some OOS public universities have merit scholarships.