We mitigated risk by using our state’s prepaid tuition plan , plus some 529’s. Our youngest attended a private HS. Only one kid in his graduated senior class attended CC. I don’t think that is a viable option to consider. You have to consider value which will often make the decision for you. Our youngest had offers from about $4000 COA (full tuition + partial living) in a 75-100 ranked school to close to $70K for a top 15 school. Ultimately he took the middle road, took our in-state flagship (top 15 rated in his program) , so all we have to cover is living expenses and books since tuition is prepaid, which happily coincided with the end of our mortgage payment. He’s expected to contribute with internships and summer jobs. We haven’t had the graduate school discussion yet, but fortunately costs are not high for engineers.
Our eldest wasn’t as academically inclined but was very frugal. He attended an early college program and graduated from his 4 year school with 1.5 years of tuition remaining in his account. We were pretty lucky.
I would err on the conservative side for your eldest. You don’t know what will happen in the future, an it is very hard to say no once you have committed down a certain path. You also have to account for tuition price increases for your younger children. You may have to allocate, say $150K for kid 1, $180K for kid 2, and $220K for kid 3 just to equalize the expenses.