These are some of my favorite online shops where I find great prices frequently.
www.whittlesfabrics.com
www.stitch-n-frame.net
www.quiltsrjewels.com
www.mainstreetquilters.com
www.beverlys.com
Some like Whittles are discounted year round, others have special sales throughout the year. Stitch N Frame has Thursday sales. Check them out...I've good luck with them all.
Also, there's a website online that's going out of business. Fabric is now 50% off. www.fabricandetc.com