Some people will argue this, but in my opinion, banners are a commodity, temporary, budget product to begin with, using ultra-premium materials isn't doing you or your customers any favors.
That's not to say that there are cases where using top-of-the-line material isn't warranted. I won't use anything but Bantex's 18oz double-sided material for any banner going over the road, or for boulevard banners, and that is high-end and expensive material. But for your typical 3'x6' sale banner or promotional banner, using Bantex's 13oz vinyl at $.50 p.s.f. is pointless, it'll cost you a sale.
I'm all about a quality product, but you have to find the balance between using good materials and selling your customer what they actually want or need. In the thousands of banners we print, I have yet to lose a sale because we don't use the ultra-premium American made material. I use quality material (Ultraflexx). It's not the very best out there, but it's really good, very consistent, prints well, holds up as expected, and meets my customer's demands, and I only pay $.12 p.s.f. for it, which allows us to remain competitive (which, by the way and contrary to some people's ways of thinking, is not a dirty word).
The same applies to just about anything. Why would I pay $90 a sheet for Dibond brand ACM board when I can buy generic Polymetal or MaxMetal for $55? $100 for a sheet of Alumacorr when I can buy Prime Panel for $70? The end result is the same, my customers are happy that we find ways to work within their budget, the sign will last as long as it's needed and then some, so everybody wins.