I know a lady who quilted, who stock piled fabric for many, many years. People knew she quilted and would give her their scraps and left over yardage, and some of it was very old. She made quilts to sell, and there were complaints because some of the fabrics rotted. I personally wouldn't buy 30 year old fabric not knowing the history of how it was cared for and stored, but on the other hand, we see really old quilts that are still in good shape, so who knows.