My S owns 3 tuxedos - black, white, and tails. He got his first tuxedo in 9th grade for concert band. He has worn it 4 years of concert band, 4 years of school orchestra, 2 years of community orchestra, 3 years of youth symphony, two summers of festival/camps, various gigs, and 4 years of college (when not wearing white or tails). In addition, he wore it to two proms, and his brother wore it to one. It is polyester, has an adjustable waistband, and still fits. We bought it through the high school, and paid $119 for it. I think we got our money's worth. As far as I know, it seems to be indestructable.
He bought his other tuxedos from these sites:
http://www.premiertuxedos.com/tuxedos56K.html http://www.awesometuxedo.e-businesse...oduct=under200
Concerning fabric - since all the kids in HS got them from the same place, they all had polyester. That must be de rigor around here, because the youth orchestras, etc, have all been similar. In college, their main concerts are in tails. He has never expressed any concern over fitting in, so I guess he has what most have.