Welcome, and congratulations. You obviously killed it in HS to get admitted at the Nerd Farm for engineering.
For clarification, what is “ECE”? Is that electrical and computer engineering? Do the EE/CE and ECE programs feed into similar career tracks?
Would CMU accept credits and allow you to graduate in three years?
I know you are comparing the costs of the two schools, but how do they compare along other variables like campus, culture, class size, undergrad research opportunities, etc.? Which is a better fit? Have you visited both campuses?
To what other schools were you accepted? Is another school even still in the running?
I used to work with an MEP EE in Chicago whose son was accepted by multiple top engineering schools including UIUC and MIT (or was it CalTech?). The son wanted to go to MIT for undergrad, but the father told him he would not pay for it when the son could go to UIUC (his in-state flagship) for half the cost. If the son wanted to go to grad school
after completing his BS he could go to the big name school then. This is a bit different situation than you are in because UIUC was closer to MIT in the rankings, reputation, etc., but it still is a good strategy.
It is my understanding that when recruiters look at students in an honors program at a strong, but not top 10, university it carries a lot of weight. In crass terms, NC State is #30 in engineering, but recruiters may think of students in the honors program as coming from a top 15 school. In addition to the education a school provides, recruiters are relying upon them to vet prospective employees; honors programs provide a more rigorous vetting process that is marketable. (CC members in tech please chime in if I am off the mark.)
Assuming there is not a downside to NC State you have not discussed, it appears to be the rational choice, especially if you can graduate a year faster than from CMU.