Colorado Academy costs $30k/yr, and as my friend who sent 2 kids there says, ‘that’s just the first $30k; they give you plenty of chances to pay even more throughout the years’ They do, of course, have scholarship students too.
I don’t think one person who intended to go to CA will think twice about it because their kids can’t apply ED to Tulane. In fact, it would surprise me if another kid from CA applies to Tulane at all in the next few years. CA will blackball Tulane as much as Tulane is restricting them and the counselors won’t suggest it as a favored school. It’s not like Tulane is as well known as Harvard or Ohio State or Duke or on TV every Saturday for football or basketball. (it is a fine school, but it needs to do marketing to attract applications).
My friend’s son went to Yale, along with 4 friends who had all been friends from Kindergarten (CA starts in Pre-k4, but they only attended CA from 10th grade). That class had 12 (16?) NMF. I play bridge with a woman who was a counselor at the school and she said to me "oh that was a very special class’. It was 25 years ago and that class is still talked about with awe. The counselors know every kid, and know them well.
I don’t think it will be a problem for CA as the students will just settle for Yale or Vandy or Stanford instead of Tulane. It may be the case of one family just not following the rules (there are rich jerks everywhere who think they don’t have to follow the rules), but I really doubt it is common for CA students to take ED lightly and back out for no good reason.