I feel ya, dawg. I know this conundrum well.
Unfortunately, @anxiousenior1 has a point. Schools don’t like candidates committing to ED and not attending–did you and your parents and school counselor have to sign an agreement that you would attend if accepted? In any case, you might just choose to NOT take it. It’s not like Duke can throw you in jail for not choosing to pay $70k a year or whatever your EFC is. There is a moral obligation, a hand-shake agreement of sorts, to go to Duke with the ED. And how you stand on that is your choice. Certainly not the end of the world if you have changed your mind. It happens, everywhere.
I know Barrett very well, and Michael Crow, the President of ASU, is the most sought-after college president for a reason. He and ASU have created the most innovative and uniquely successful school in the country over the last 10 years. Barrett students get those great facilities, personal attention, outstanding living arrangements, first choice in research opportunities and internship/coop interviews. They have all of the Fulbright and Marshall engagement support. @NerdyChica’s logic is flawed–just because an endowment is higher does not logically or actually translate into having better opportunities. And at Barrett, that is certainly true. If you want to boast about endowment dollars, go to University of Texas-Austin or Harvard.
You can’t go wrong with either choice. But the question of your obligation to your commitment on the ED is your own decision. Is what you stand for the same as what you want?