Scholarships for traditional universities are pretty hard to get unless you have really strong academics. And generally the odds are stacked against you to go to a top tier university if you're coming from a low income background.
Keep in mind that if you graduate from Make School in 2-2.5 years, you'll start earning earlier. So the ROI on the $70k is really strong!
Research Universities are definitely the way to go if you want to go into the research focused ML/AI side of things. We're being explicit that this is an Applied CS degree for that reason. But for most tech careers the traditional CS degrees aren't as relevant, including for Data Science jobs (we have a few recent alums making north of $150k as Data Scientists). And you can always go back for a masters if you feel you need it.
Have you visited 42 or been through their curriculum? What parts do you feel are better?