I think that is a person question that can be answered differently by every person you ask it of. For myself, I only like scrappy quilts and would never make a quilt with only a few coordinating fabrics so the more the better! I don't like batiks all that much so I don't buy those but I do buy lots of FQ's, layer cakes, jelly rolls and charms...and when i decide what I am going to make I then go out and buy solids or coordinating prints of similar colour for borders etc. The only fabric I would buy yardage of would be whites or tone on tone whites.