Whittles is a favorite shop for quilters in my area. It's about 60 miles from where I live. They are super nice people and ship very promptly. If you can visit in person, their prices are even lower.
You can find good quality fabric there along with the cheaper stuff. If you'll stick to brand names you recognize, you'll probably be better pleased. I think much of what Whittles carries is either over runs or discontinued fabric, which is why it sells for so much less. They have great backing fabric at awesome prices too.
I also love Connecting Threads and have ordered from them a couple of times. I thought the fabric was good quality and pretty colors. I don't know how they sell it so cheaply!