re: 529 Plans - Are they worth the investment for Children?

I am targeting and on pace for $100k per kid by contributing $4800/yr. At 7 and 8 years there are just too many unknowns, but I can adjust contributions later if needed. While scholarships would cause an overage in the account, I would be elated if either it allowed me to reclaim my investment even with penalty. On the other hand, out of state tuition, graduate school, housing, etc. are variables that could impact total costs greatly if just considering a savings based solely on 4-years at a set tuition. I'm confident they will need the majority of it, but if they do not due to scholarship I will be happy to pay penalties and spend the money on something else when they are out of the house.