I'll add this thought for the ump-teenth time: SALES!!!!! Hit all the sales and snag the highest quality fabrics you can find for as low a price as you can find.
I happen to know that fabrics are often sold at below cost through local quilt shops, and their on-line outlets. Once a non-basic fabric has been on the shelf for nearly a year, it is pushed out the door at a price below the shop's cost per yard. Many times it is sold for less than half the wholesale price just to make way for the new fabrics.