I agree that this is a very personal choice. When other quilters are talking, the question of "how big is your stash?" usually comes up. Since I am a scrapbooker as well, I quickly realized that buying 12 x 12 scrap paper for my "paper stash" was more easily managed than buying fabric everytime I saw something I liked. A very dear friend gave my sister and I a lot of Civil War fabric and we immediately put it to use, so that stash has dwindled quickly. This gift of fabric fueled our creative juices and as a result many beautiful projects were completed. I don't have a lot of storage and disorganized "stuff" makes me nervous so I try to make an effort to buy only what I need for specific quilt projects.
I frequently sort through and give away fabric to the Thrift Store that I don't think I will use and no one to pass it too. This way, somewhere - someday, another quilter will get so excited that she found fabric at the Thrift store for her/his stash and that person will be very happy!!! Pay it forward!