when a store is (large enough) they can order in bulk and get better deals---they may order 500 yds of something (where the lqs could only order 30 yds---they get a much better price than the quilt shop will get- same goes for books, notions ect-
the supply companies have different price ranges based on amount purchased- so if an lqs buys 5 of one book (or one of a book) they will pay almost as much as they sell it to us for- if the store can buy 20+ of the same title they get a much better price- and some pass that savings on to their customers- same reason the big-box stores can sell the same items for less- they buy larger lots of the items...get better prices.