Hi,
I'm a bit obsessive, but if I REALLY like a fabric, I'll buy 2-6 yards of it. I used to only buy 1 yard pieces but I usually ended up disappointed :-(. But, I do have over 2,200 yards of fabric (probably more than 3,000). If you find great fat quarters that catch your eye - they're fine too - they could be an accent fabric on corners or something. So, the moral of my story is buy based on how much you like a fabric or if you think there is a possible purpose for it!