I'm with Macybaby, I love me a scrappy quilt! My guild has a sale every year where members donate fabric they are through with and the guild sells it for $2/lb - they get everything from nearly full bolts down to scraps the size of my palm. I LOVE the scraps - I do crazy quilts too, so almost any size or shape of fabric will work for me, and getting a hold of other people's scraps adds so much variety to my quilts! And at $2 a pound, that's practically free. (Or so I tell myself, LOL)
I buy fabric for a lot of reasons. Because I like it, because I need it, because it coordinates with something I already have, because it feels nice, because it's super cheap and not horrible...any of those reasons can make me bring fabric home. And then there's fabric I am given - now that I've been quilting awhile people know I will take fabric. I have a handful of garment sewer friends who save their cotton scraps for me, and twice now coworkers have had a sewing relative pass away and given me access to their fabric horde. (Both were garment sewers though, which is probably a good thing as it made me take very little!)