The problem is that I can give equally strong reasons for the public side. We really do have a great public school program. Here's what I see as the other side.
1) We aren't Catholic.
In my HS class of 90 students, there were a handful (4 or 5, I think) that weren't Catholic. It certainly didn't appear to ever be a problem. They had to attend mass as it was a school activity, but obviously they didn't receive communion and it was never an issue. We did have relgion class every year as a major subject and all students had to take it. So he'll certainly learn a lot about Catholicism, but I would hope (and truly believe) that his beliefs (or lack of) will be respected. Something I've always found ironic is that I learned FAR more about other religions in my Catholic schools than my puclic school friends ever did. In 10th grade, our religion class was "World Religions" - so we spent the year learning about Islam, Judaism, Hindu, and other Christian relgiions. Most of my friends from public schools never learned anything about religions other than their own.
2) JROTC -- I know he'd love it, I worry about how much encouragement there is for them to choose a military career. The military is 100% out for my kid, because he's got a medical condition they reject for.
This is a great concern to bring up with the school. They schould be able to tell you exactly what percentage of students each year enroll in the military, what percentage go onto college ROTC, and what don't do either. That will give you a good sense of the program.
3) Arts --
4) Languages --
5) Social Sciences --
I combined all these because it's the same basic issue: More choices at the public school. I have two thoughts on this. 1. More doesn't always mean better. In education, I have found that it is really quality over quantity. If the school offers fantastic classes, that's far better than offering more mediocre options. (Not saying the public school is necesarily mediocre.) 2. Your son only has 24 hours in the day and 8 (or so) classes per semester/year. Sit down and figure out realistically what his schedule would look like at each school. What is he REALLY missing out on? Even if the school offers 20 social studies classes, he's probably only realistically going to take 4 or 5 of them. Even if there are a dozen choirs, he's only going to participate in 1 or 2 of them. So if the lack of options means he's missing out on something he would really like to do (perhaps arabic), than that's a potential problem. If it's just a matter of 'it would be nice to have more choices' than I really wouldn't be overly concerned.
6) Sports -- program at private is definitely stronger, but that also means that a lot of kids go there specifically for sports. I worry about playing time for my kid who is talented but average height and plays a sport/position where size counts.
This is another legit concern to ask the school about. (and maybe some other parents if you can track any down.) Find out how many teams there are for each sport. At my very small high school, we had 6 lacrosse teams. So even if you didn't make varsity/JV, you could still be on a team and getting lots of playing time.
7) Money -- this should be first. I think the tuition workable for us, but we'd have to cut a lot. If he went public my son could do some summer programs on college campuses plus sports camps, drama camps etc . . . He could continue to be in the ski club (it's middle school/high school mixed). We could take trips as a family. If he chooses private all those things would need to be cut.
This is the hard one, and also the most personal. Only you know your budget and priorities. Find out more aobut the school, resolve all your other concerns, and it will quickly become clear to you if it's "worth it" in the sense of everything he'd be giving up.