Long post, but many misconceptions here. I’m not sure all posters remember (or read?) the initial situation and are responding to that. OP has some but not all funds. And a 2nd child to pay for. Money doesn’t grow on trees. What you paid for college 25+ years ago and totals, interest, etc, were freaking different.
When his friends pointed out he hadn’t included all income/assets in the NPC, he could have said to kiddo, “Houston, we have a problem.” instead, he based “affordability” on, in effect, bogus numbers, a 40-48k family cost. He’s still got that second child. And no extra 30k+, per year.
Face it, most outside scholarships are a few thousand. If that. You generally borrow parent plus loans year by year. Borrow 30k now and next year, you show that debt plus fewer working years left. Will you qualify?. It’s possible but not something to assume will “just” work out. The higher the numbers, the more fraught with risks.
The following year, you’re already 60 k in debt.
30k in PP loans (year 1) is paying back about $300/month, every month, starting late winter of freshman year. OP isn’t telling us he has an extra 300 now.
120k for the 4 years will mean about 1200/month. Interest alone will add about 50k–money I’d guess he’d like for retirement.
You think, oh, but engineers can make big bucks… the son can pay. What? Use 96k or 8k/mo,. 6 k after taxes. Less after your 401, transportation, rent, food, clothing social life, maybe wanting to get married, buy a home. You want to lock in to 1400/mo for ten years?
The above is partly based on repay calculators, things like rates can change. But I hope it gives idea of the risks.