If it's sent USPS there is 50.00 worth of insurance included in Priority postage. Not sure how much you got though.

Never heard of quilt supplies retailers asking if you want insurance. Sewing Machines and large ticket items, sure, I pay the price everytime.....but not for batting. I would call them, ask the person's name, get assurance that they will seal the plastic bag. $4 is not much...I would ask them if anyone has filed a damage claim on their batting. Perhaps there is a reason they are asking you about insurance.

Thanks to all of you that responded. You gave me plenty of great info.