“Q:Do I even need to think about tuition when buying a home? Do I need to think about future kids/expenses?”
If I had thought so long and hard about buying a house and worried about tuition, I’d never have a big house. Hashem wants you to have a large home and to fill it up with children and to pay tuitions; so why are you thinking so much, leave it up to Him to figure out how it will happen. And it will happen if you make the first move.
It may seem hard, but it’s not up to you to make these cheshbonos when you’re doing the right thing. Some things, especially the cost of maintaining a frum lifestyle don’t make sense on paper; but Hashem comes through.