Lot’s of great discussions on this thread. I’ll add in the suggestion to be as opportunistic as possible.
For example a semester or full year abroad can actually save you money. The private schools that D has looked at indicate that you pay the foreign school’s rate rather than your home school. At one of the school’s she’s applied to, that would be a $20K savings in tuition (I travel for work and rack up the miles, so travel costs for us are not likely to be an issue). At her top 2 (OOS publics, $45k/yr COA) we would pay the in-state rate when she’s abroad. Since she’s always planned on studying abroad for a full year, this one is a fantastic benefit for us. FSU (in-state for us) even has a First Year Abroad program where OOS students can end up getting in-state tuition after their freshman year when they spend their first year at one of FSU’s abroad campuses.
Another thing to look at, especially if your kids are considering science or engineering is the potential to participate in a co-op program. A good co-op program will ensure that participants are placed in paid positions. For the 2 OOS publics that D is looking at, she should be reasonable able to earn ~$30K towards tuition over three terms.