every school is different. Only about 30+ Unis meet full need and are need blind. BC is one of those. With the exception of a dozen merit scholarships, BC is essentially need-based only.
They spell out rather clearly how stacking private scholarships work. (first eliminate $2400 work study…) What we don’t know from OP was how much was the Expected Contribution and in what composition (Pell Grant, federal student loan, work-study..) before applying the outside scholarships and after.
BC’s COA is ~$97k if living on campus. $5k less if living off campus, and $17k less if commuting from home.