if its a single piece I LOVE...I buy 3 yards....figure I can find sometime in my stash or buy 'go with' fabrics at a later date.
If has co ordinates that I like as well, I buy at least 1 1/2 yards of each (figuring I may find something to go in my stash),
We have a local fabric store that is a full block big (honest!!) and they have a 40% off sale about every 6 weeks....I try to buy TOT/blenders in 2 1/2 increments if I have the funds then.
I keep what I dont use for one project for other projects or scrappy quilts