If he’s good enough to play at your state school, which I assume is a D1 school, then he might qualify for an athletic scholarship there (even if it is a partial one), and then the state school might also give him a financial preread. It’s not a perfect situation but it isn’t as grim as knowing nothing about the state school’s financials. If he’s not being recruited to the state school but you still want to compare a merit offer, you can explain that to the D3 coach. That’s the type of stuff they are willing to work with you on, but they want you to WORK on it and not just say “well, we want to see what State U has to offer so we’ll get back to you in April.” I don’t think they can wait that long.
My daughter could not have played at our flagship (the team was ranked 4th in the nation at the time) so she looked at other D1s in the state and at a lot of D2 schools. She was recruited to a bunch of D3s and they would have discussed merit but she decided pretty early that she was not interested in small LACs as she wanted engineering.
By the time she was going to commit, we had the athletic offer and a pretty good idea of what the merit aid would be at that school and any others still on her list. She knew she’d have Bright Futures she could use at any Florida school. There was some financial risk in committing but we had a pretty good idea of what it would cost. If the merit didn’t come through, she would have taken a gap year.
We could have kept negotiating with other schools, mostly D2s, but she found what she wanted. There is a point where you do just have to take the leap. It’s not unheard of for state schools to have their merit awards out by the ED deadline, especially if the merit is ‘guaranteed’ because of test scores and gpa, or that a coach would know what is ‘typical’. My other kid was in that situation and we just figured out what her merit would be by the chart.
I think you’ll know a lot more about the financials at schools by Oct or Nov of senior year for the athlete. You may learn more about your FA package (because of the complicated divorce arrangement) if the older sibling also applies to the state school and a few private schools. You do learn a lot about FA for the first kid. Unfortunately for me, I learned a lot but my kids went to school the same year, so if I’d had another kid I could have used all that knowledge!