That is a nice summary of many of the issues, NotSoGifted! Ultimately, this is so difficult because we don't know where DS/DD will end up for college. We also don't know in which college/colleges they may end up earning credits while in high school.

In DS' case, he will be required to take at least one math course at one of the area colleges in order to graduate high school. Due to CC, the highest level math course at the high school is AP Calculus BC, which DS is scheduled for sophomore year. He can take it easy and take AP Statistics as a Junior but he needs a 4th math course.

I need to figure out how good/bad the community colleges are as well. They are preferable to the university from a financial consideration. Why pay thousands for a course when you can pay hundreds or even zero?