According to your post, WashUStL-Olin “sends a lot of kids to the big 3 consulting firms” and your career goal is to become a consultant. You assume that you will receive a full ride scholarship offer from this school.
Really depends upon the actual COA for each of your 3 options.
Without more COA details, “free that gets you to where you want to be” versus “full pay” at your other options, leads to a clear choice.