Thousandsofbolts.com is an excellent source. I paid $4.15/yard for fabric I could not find at any of my local quilt shops and I have access to quite a few. Shipping was reasonable and I received the fabric in about 4 days. Very impressed and am telling everyone.
I have also shopped at Hancock's online and have had very good results. Yardage is cut generously and I received in about 4 days as well.