I used to do that a lot. But for some reason I have stopped. I used to rush out when Fabricland in Canada had their buy 1 get 3 sales. But most of that fabric just sat in my stash. So now I just buy fabric that I have a specific use for and a little of the "it is just nice".
I still have tons of fabric and I am sure I could sew for the rest of my life and never use it up.