I've only bought FQs once or twice-not enough fabric to do anything with for me.
I usually buy 1-3 yds (depending on how loud the fabric calls to me LOL) and try to add to my stash what colors I'm lacking. I have a small stash but try to keep it varied.
I recently ordered from ConnectingThreads and they had a quilt kit on sale for $17.00. I liked the fabrics but not the pattern and there was lots of fabric in it-worked out to about $2.50/yard.
I run into probems with backings and usually run out to get fabric for that after I finish the quilt. Have to watch for sales on backing fabrics.