When I am working on a quilt, I would say 85-90% of the time the entire quilt comes from my stash...backing, binding and all. When do I build my stash? When I travel, mainly. I have a few favorite local fabric shops, too. When I see a good sale, I stock up. I don't buy much fabric on line at all-I much prefer to buy in person. Shopping on-line can be dangerous and my husband does enough on-line shopping for the both of us. He admitted that himself.
These were both on sale and both fabrics are ones that I could use in a variety of quilts. Or I could see using them on quilt backs. That is when the words "I'll take the rest of the bolt" slip out.
There you go! Way too much info on how I buy fabric. I hope that those of you who have asked this question have found the answer helpful.
So, how much fabric do you buy at a time? I'd love to hear, if you care to share!