IMHO the quality of fairfield batting has degraded over the years. I have had several clients give me Fairfield 80/20 to use. While it is funcitonal, I find it has places where the batting loft is inconsistant (spots where it is very thin) and it is very fragile. Maybe the cotton would be better. I would try to inspect it carefully before purchasing, especially giving a tug on the corner to see if it tears easily. If it doesn't and what you can see looks consistant in the loft, I'd say go for it.
Connecting threads is having their batting sale going on right now at 30% off. Free shipping if your order is $50 or more. The deal isn't quite as good as JoAnne's though. The 90 x 25 yards works out to be quantity as 8 queen size battings plus one yard left over. The Hobbs at 100% cotton at connecting threads would be $130 so more expensive.
I have never tried Hobbs 100% cotton as I prefer the 80/20 myself. The Hobbs 80/20 would be comprable at $112 for 8 queen size batts.
http://www.connectingthreads.com/bat...BattingSaleOC3