Email Carleton Admissions and say you’d really really like to commit but are $1,000 short, which is a lot in the current situation for a low income student. “Is there an institutional scholarship I could apply to that’d help bridge that gap?” Odds are high they’ll say they can offer you an extra $1,000.
Don’t deprive yourself of this amazing opportunity.
Borrow the subsidized amount and put it in the bank. This way, you can use subsidized loan money only should you need it.
No, books aren’t $1,000 a year. You can use the library. You can rent books. You can buy used. You can even discuss your predicament with a professor and see if they’d have an instructor’s copy they could let you borrow for free.