If you are sending heavy things, a flat rate mailer might be best as it is one price. You can order APO box which is the same as a large flat rate mailer. There is a $2 discount most times when shipping these to an APO/FPO. If you fill out and pay online, it can be less. Here is a price calculator through USPS.
If you are sending a large amount of items, we suggest a larger box and ship it ground through the USPS. The price will change depending on where you are located. This is how we send our boxes.