If I could make a couple suggestions:
I would actually agree against YSL L'Homme as I think it might not past the "not overused test". It is readily available at most stores, so the potential it could become even more popular is there too....
Also, while Lui is a great scent, a) it's not cheap, which might be a concern for a younger guy and b) it could be a little TOO animalistic. Also to me, it would seem somewhat out of place with a high school guy. Just my opinion though. Plus I really don't see girls that age liking it, and let's be honest....that's pretty important! :P
A couple suggestions I would throw out:
Aramis Havana
Chanel Antaeus
To me they are VERY manly and you are extremely likely to be the only dude at school wearing them. I can't say they are rock-bottom cheap, but I still think reasonable and smell like they cost more than they do. Personally I find them both pretty versile and wear them both day and night. Good luck!
***If I could add one that I think is very versatile, but may not fit your other categories is Chanel Egoiste Platinum. The only downside is that it would be more expensive than the other two. On the plus side you could try both that and Antaeus at the same counter. Most high end stores like Neiman Marcus, Nordstroms, etc should have both.....