Purdue would be one of the more competitive environments, one I would advise against for someone looking for more collaborative. I think admitted students day will help determine if that matters.
It sounds like UMD is the best value + fit combination, good CS of course, etc.
I’m a Northeastern CS student so I’m a bit biased, but Northeastern does have a truly unique introductory teaching curriculum. It’s from the ground up, and often even those with lots of experience get a chance to rewire how they think about problem-solving and computer science. I’d recommend reading/passing along this essay:
http://www.ccs.neu.edu/home/matthias/Thoughts/Developing_Developers.html
I actually help to TA that intro course and would be happy to rant about the value of the curriculum difference if desired, lol.
The other big positive Northeastern has would be location, which is amazing and really adds to the experience.
I do highly recommend Northeastern for CS, but these are all great options. Whether those points above make it worth the extra money depends - where does it come from? If any of it is loans or financial hardship, given how good the other options are, it’s absolutely not worth it.
OSU is a great option if even UMD means loans/hardship, but I think UMD, especially when it comes to AI/ML research, merits the extra cost.