I have chosen to use sheets for the backing of quilts I plan to give away. I go to the Thrift stores and purchase Queen and King flat sheets that have been used enough to make them soft. While I am not a hand quilter, this keeps my costs low. The Long Arm quilter I use charges $40 and $50.
A few of the quilts I made for family, I pieced the backs. The soft sheets give a good feel to the quilt for the persons using them. Some have been in soft colors and other have unusual patterns printed on them. They catch my eye and the quilter has told me that when her customers come in and see them, they remark about how pretty they are.
It truly is a matter of choice and the type quilting you are doing. This is what works for me. The less I spend, the more I can make and donate to Battered Women's Shelter.