Right after Thanksgiving JoAnn's usually has a 50% off on batting, and at the same time they run some other promotion that can be combined with the batting sale. It is not always clear from the ad, or from the web site, that the bolts are on sale, so you may need to call and place the order in person. I got a bolt of each this year for 50% off, then also used a 10% off coupon, and then got free shipping, which I hadn't been expecting. How great is that!
Mine came to an average of $3.25 per yard. Since W&W is more expensive than W&N, it would have been even less per yard if I had only wanted W&N. I just wish they carried wider than 90" in the bolts.
Forgot to say, if you have an AQS membership, you could use that 10% off combined with any 50% off batting sale and not wait for Thanksgiving!