AB Duke winners routinely turn down Harvard and Stanford even when money is not the deciding factor. Other schools simply cannot match the individual attention that an AB Duke scholar receives. The AB program is really like the American Rhodes in some ways. Duke is the only top 10 school that offers a full ride merit scholarship. Your odds of being a Rhodes or Marshall scholar are exponentially higher if you are an AB as opposed to a regular student at Harvard or Stanford. Not really an apples to apples comparison.