Re: 1 oz csm
If it's in pristine condition, yes
But be aware that often clearance glass isn't ideal. It may have gotten wet, have flaws in the construction, or a few other less desirable environmental conditions. If it's damaged, particularly by water, it won't wet out properly. Price new material from whoever you're buying your resin from. Then decide if the price difference is worth it.
If the seller is a reputable shop selling you the end of a roll, that looks like it's had CSM pulled off it recently, consider it. But again, why is the seller selling it so cheap? Does whatever they're telling you fit w/ what you see when you're in their shop?