It really depends on your budget, but less than $11 per class seems like a good use of your $$ as long as all of the teachers will be using it. Nothing worse than to buy things and have them sit in a closet only to be discarded at the end of the year.
If you don't expect too much from me, you might not be let down. <img src=images/smilies/smile.gif>
Couldn't you make banners out of fabric or even paper. Our school does something like this (without PTO's help) and they use paper than laminate. Laminating is expensive, but it lasts all year. If you use fabric, you might be able to find canvas or extra wide felt for cheap. I just bought 72" wide felt for $3 yard on sale. You could cut two 36" squares per yard for just $1.50 each. If you look now, there's lots of felt colors in the stores for Halloween costumes. Maybe they're proposing something fancier or more professional, but seems you could DIY and save a bunch of money.
At our recent PTO meeting we had a teacher request to purchase banners that could be decorated by each teacher to hang outside of thier classroom. Since we have 26 class rooms the estimated amount for purchase would be $285. The teachers have addressed this request as beautification and unificiation of our school. $285 seems like a lot for a banner to hang outside the door of each classroom. Has anyone every done this, and is there a cheaper alternative?