But when it comes to saving your projects, that is a whole new story. A lot is going to depend on what you want to do. I have a terabyte on my computer and it is almost full. I also have several external drives that I need to set back up to my computer and a DVD burner.
Items that you are going to want to use frequently you are going to want to keep handy. Your layouts should be backed up on an external drive as well as burning a DVD of them. Better save than sorry. I need to do that to mine and free up some space on my computer.
If you don't have the space on your computer, I do suggest that you invest in an external drive. The prices have really come down and you will be glad you have it.