I wish I had that kind of money when I was in HS. I remember working my ass off all summer long so I could afford to buy an Atari 800 (yeah, this was a looooong time ago).
There are very, very few reasons I'd recommend the 13" MBP. In its current form, its performance is laughable when compared to a 13" MBA. You are basically buying an aluminum-clad plastic Macbook and for that reason I'd suggest the plastic Macbook over the 13" MBP. Seriously, its the worst buy in the whole Mac lineup now on a price-to-performance ratio. The only people who defend it are those who are clearly jealous of the 13" MBA out-performing it in benchmarks.
That said, I can see where the optical drive would be of value to a high school student. You'll use it for ripping, watching ordinary DVD's and maybe even playing audio CD's since this could be your only media center in your room.
I'd say go Plastic Macbook and take the $500 you'll save and sink it into something like a really good backpack or maybe some software.