Different areas of STEM can vary quite a bit, but all the MIT degree (and, let's be honest, that's the absolutely cream of the crop example) will do is to pretty much guarantee an interview and have a favorable first impression.  Once you are in the door, the experience you bring to the table is going to count for a LOT more (IT: Did you program a useful utility during college?  Chemical Engineering: Did you have a an internship at a chemical lab/factory?  Biology: What sort of lab experience do you bring to the table?  Etc, etc)  And if you are anything less than a MIT, it will mean a lot LESS.
The difference between a Penn State degree ($17k/year for in state tuition) and a two year community college followed by a commuter life to Youngstown State ($8k/year for in state tuition) is almost nothing on the job market.
That said, I think there is some huge benefit to "living away from home" and not living the commuter life.  The question each family needs to answer for themselves is if that benefit out weighs the inevitable college debt.