I agree, there's no such thing as too much fabric. If so there wouldn't be more at the store
I always figure what is needed then I add what is wanted. Without stash I wouldn't have a clue what to start next. I look at it like how I cook...I see what I have in the fridge and the pantry and pull out the things I want to start with, then add to it as necessary. You'll see after you've made a few quilts, as your skills grow so does your stash. It's a win-win.