what is equal?
We have step and children together. They will be treated equally as in that we will pay for college. Our youngest has a 529, the others do not. There is plenty of time for the $$s for the youngest to grow tax free. The oldest, not so much, so that is coming out of the stache.
So, while we feel we are treating them the same, I guess if they go widely different priced schools, the cost of treating them "equally" would vary substantially as well.