Yay for being ready (or almost ready) to print an album!
Like the others have said, Shutterfly runs various sales. You can upload your layouts as you have time, and when you are ready, double check through your album (I have accidentally skipped a page before), and then place your order.
If it is for a sale, they sometimes run short and usually end on a Sunday if I remember right.
I wait until they have their flatrate sale. Then you can get up to 100 pages I believe, for one set price! BEST value!