Sometimes FQs are less expensive than yardage because they're on sale more often. I buy them when I'm short on a value (light, medium, or dark) Usually lights because I tend to buy the deeper fabrics and need fillers and more contrast. I also don't have a problem using different pieces of the same value when the pattern calls for just one fabric. I don't mind having scraps left over because I love scrappy quilts. However, I also love my stash and don't mind cutting the yardage for however much of a fat quarter I might need. See, the more I use my stash, the more fabric I can buy to replenish it. Ah, what a joy.