There are many reasons why a quilter will choose one LQS over another when it's time to buy fabric. There is one store in my shopping radius that I will not go to because they like to choose colours for you, trying to make sure everything is matchy-matchy. The last time I was in there they tried to make me feel like I had no sense whatsoever simply because I did not know the producer's name for Malka Dubrawsky's new "Stitch in Colour" line of fabrics. Looked at me like I was crazy, they did: she actually asked me if it was a real fabric line.
It may have had something to do with me not looking like a typical quilter (purple faux-hawk and all). Meh.
However, at my "home" LQS they appreciate that I know my way around cotton. In fact, they never offer to help me choose fabric.
Why, you say?
I have a queer little (awesome) talent for colour memory. I do not have to take a focal fabric in and then match colours using the dye dots on the selvedge. All of my colour choices go together because I say so. I can see a colour a few times and just know what will look good with it. Or, as in the green quilt, I can match very similar colours and it'll still look good together when I get them home.
Today I bought these greens to supplement the scraps I already had.
And I chose a lovely unbleached muslin for the BG. I hope they'll still have some when I have the money to buy it. (You were right about the cream, Diane.)