I'll tell you a secret. I work at a Target, right next to Justice. I went into Justice one day after work (in my red-n-khakis) trying to find some things for my daughters.
The very trendy teenagers (working the register) were all "OMG! I love Target! Everything's so cute there! I shop there all the time!"
I figure if Target is good enough for 16 year olds with their own spending money, it is good enough for my tween-teens trying to spend my money.
As far as Aero, Abercrombie, I follow the same shopping choices as I did for myself in high school. If I am going to spend the $$ for name brand, I am going to plaster that "name brand" all over the hoodie, tee shirt, jeans, whatever. But the cami, undershirt, plain, no label white tee... we're buying Target thank you very much.
I would worry about fit... but not so much about quality. Teenagers have fickle tastes. They're not going to wear anything long enough to wear it out
Platos closet, neighbors, friends, resale shops are great places to find stuff too! Don't spend and arm and a leg on that trendy stuff... especially in the name of "quality."