The USPS has these awesome boxes that are one flat rate to ship no matter the weight. It works great for us sending stuff back and forth to MN. The trouble is when you don't have a lot of extra cash, you don't want to pack more than one. So I took one large flat rate shipping box and filled it with all of this.
What's the secret? Space saver bags. The one problem if it pops during it's trip it will make quite the mess. Lots of fun stuff heading your way Mom!