I have bought at
http://www.fatquartershop.com a number of times.
They are not cheap though, although they do have a clearance section. Kimberly (the owner) is lovely to deal with and all their fabrics are lovely.
I actually just ordered 3 yards of clearance christmas stuff to make a tree skirt.
Here's a link to the sale section:
http://www.fatquartershop.com/onsale...Page_Id=15&T=1