I was 15 when I first got contacts.
DS11 just got them this spring. He has been VERY responsible with them. (and goodness knows he can TOTALLY be an irresponsible middle schooler...) It really seems to have improved his baseball playing!
They are disposables, so run 12.50-17.50/box of 6. (12.50 if you spend $180 for bulk purchase). He has had a couple rip IN his eye...but after speaking to others who use them, apparently this does happen. He did "lose" one, and we found it dried up on the counter a few days later! Each pair is to be used for 2 weeks or so, so that is $2-3/week...NOT bad.
We go to America's Best, and you can order online, as well, though I have not tried yet. (DH's cousin is an optmetrist, so need to call to see if he can get them any cheaper for us!)
Good luck!
(PS our decision was based on our optometrist cousin...he said when DS could be responsible for things like keeping his room clean, homework, showers, without parental nagging, he was ready. He is not perfect, we do have to remind occasionally, but overall we are pleased)