It’s going to take you a lot longer to have “accumulated some capital” and reach your “ultimate goal” if you start your career $300K in debt.
I don’t always agree with those who advise posters to take the cheaper option if schools, but in this case you would be crazy to choose USC.
I remember a similar post several months ago. Were you previously deciding between transferring BU for sophomore year, applying to more selective schools and transferring junior year, or even attempting a second transfer?