There are a couple of other considerations that I haven't yet seen in this thread that have made a difference for us (2 kids now in high school in the US midwest).
One is that we made a choice to send our kids to public rather than private school. Although the public schools have not been perfect, overall they have worked out okay for our kids and I don't think the value added by the local privates would have warranted the expense. (Here is a
link to a past post about what we like about the public high school our kids go to.)
Early on, we did save for private school tuition so we could have private school as a back up plan if the public school got too bad. It helped me in advocating to know I could walk away from the public school at a moment's notice. We eventually took those savings and put them into 529 (education) accounts in our kids names. Earnings in these accounts are tax free if used for college expenses. Our 529 funds have been invested in the stock market and have grown much faster than the rate at which college expenses have increased, although we were quite lucky in making a big investment in 2009, when the stock market was at its lowest.
The upshot is that our 529s can now more than cover the state flagship and can come close to covering privates.
