the last few months I have spent well over 1000 but this is not normal in any way shape or form. This was done to help me with my project for the soldiers.
Generally I will only buy if I have a project or if I happen to wander into a store with fabric and see something I really like. Since I live in the woods it is not to often that I wander in.
My stash grow crazy 2 years ago when visiting my brothers in Maine. I found these lovely ladies that were having a yard sale with lots of quilting fabrics so low I had to buy some of it. My brothers, who were with me and do yard sales all the time told me I should make them an offer for all they had. I felt bad to do that since their prices were so good but as things went, the boys took over the sale and I ended up buying every bit of cotton they had. I had to ship it home because I didn't have room in the car to carry it. Even with all the shipping cost, I ended up paying only 33 cent per yard. The rest is history.
And this my friend is how your stash gets growing! Good luck in your building but remember to always look for deals and never settle for fabric you don't really like because it may never get used.