You're right about why LQS are more desireable; it's not just the fabrics and quilt specific tools, it's the knowledge of the people who work there!
I'll go to a Joann Fabrics, Beverly's Crafts, Walmart for cheaper fabrics but only if I do not need any advice. I go to one of my 2 LQS when I have a really special project requiring opinions, math for fabric amounts, or other help. My thanks to them is buying the fabric for that project there. These days I go there mainly to look and plan because I can't afford to buy fabric and all of you are helping me with questions, whether or not I actually did the asking.