Thanks to all who have replied so far.
If I can put on my "whiney hat" for a minute, I guess I'd like to end up in a situation where I have neither undersaved nor oversaved. I don't expect to have saved exactly the right amount or within $100, but it'd be nice to be within $10K or so. Unfortunately, the dispersion on costs is simply too wide for my desire to be reality -- between various college sticker prices, scholarships, loans, grants, aid, travel, tax benefits, extras, inflation, investment returns, student work study, their mother's contributions (ha!), pocket money, pizza, and beer, it seems like the cost can easily vary between $5K and $50K a year.
To meander on my own thread a bit...
The additional complication in my own case is that if I use the $12K per year figure that I currently do, my projected FIRE date is about 9 years away, which would be when my oldest would be about done with college and my second would be about to start, and my third probably wouldn't know where she wants to go yet (she'd be a sophomore or junior by then, I guess).
I'd want to be equal/fair to the three of them, so it doesn't seem fair to say to the eldest that he can go wherever he wants and then put the youngest on a budget (because I'd be retired on a fixed income by then).
To put some perspective on that coin, the difference between, say, an average public university (@$10K/yr) and an average to good private university (@$25k/yr) is about equal to 1.5 years of living expenses for me. 3 kids x 4 years each x 1.5 = 18 years of living expenses. So in effect that money could go to either private schools for them or nearly 2 decades of my expenses. I'm not making any decisions or value judgments, just saying it's a big impact.
My parents are also well off and old, so there's some likelihood of an inheritance. It could also vary between $0 and...well, a lot. And I know the first thing they would want that money to go towards would be extending the deal they gave me (go anywhere you can get into, we'll pay the bills) to my kids. Even if I didn't see eye-to-eye with them on their perspective that the best colleges are worth the price, I'd have a hard time not honoring their wishes since it was them who earned the money.
Too many variables. I guess I'll just take it as it comes and know that if I make good decisions that my kids will probably be able to get a very good college education.
2Cor521