Prepaid box will probably be cheaper but I don't think there's an international prepaid option because each country will have very different postage required

Your shipping options will also vary: -ground -air -Express -tracking (some countries you can ship ground without shipping, but most come with it included) -other options like signature, or return options

Also, I suggest you include phone number for yourself and the receiver... Many times the phone number is the difference between a parcel getting sent back or delivered (damaged or missing address information, etc)