It is pretty much all about the audition for musical theatre and applied music majors. Of course, you want to have some EC’s and a solid performance resume, and you have to meet the school’s minimum academic criteria, but the decision will hinge mainly on what the student brings to the audition room. Not saying that having a great application won’t help, but it won’t get you in, and if you don’t meet the required artistic bar, the rest of the application will be largely moot.
Meeting these criteria will be an interesting challenge. Depending on how you set your criteria for “nice,” “great,” and “hard to get into,” nice schools with great music programs tend to be very competitive and expensive. They know who they are and they know what they are worth. And lots of people know about them and want the same thing that you do. Sorry to be a nudge, but demand far exceeds supply as you move up the pyramid of colleges, and the laws of the market pretty much dictate what happens when that occurs. There are great choices out there for everyone, but you may have to look far and wide, and think hard about your criteria, to find a school that will meet your objectives.
The easiest way to lower costs is to have good grades and test scores.