I recently needed to start closing up my Kunming home office and return to the U.S. for business. I'd imagined being here much longer, so I actually purchased a good bit of "dongxi" for my place. Suddenly, I needed to leave and I immediately figured I'd need to sell/discard everything, due to the price of international shipping. But, there turns out to be just one exception to this: China Post Surface shipping. Their rates for surface (sea) shipping are low, by anyone's standards.
If you can put up with the 45-60 day delivery time, its the way to go. Anything up to 1kg is 83.5 RMB ($13.58). For every kg over this, you add 20 RMB ($3.25). The maximum shipping weight is 30 kg. The maximum size is maximum package length + maximum package circumference, up to 3 meters. So, there is quite a bit of latitude for what you can send. The biggest, heaviest package you could have would be $107, but this is unlikely. Most of my boxes were only 9-10 kgs. The biggest was a digital safe that I really liked that was stuffed with other things. The parcel held about $600 worth of stuff and cost about $83 to ship.
China Post gives you a nice value-add, too. In addition to packing your stuff, they provide these nice, heavy-duty boxes, bubble wrap, heavy-duty tape, AND they apply this heavy nylon strapping so your box can't burst open, or be easily tampered with.
But, there are some things you need to know:
1) The China Post folks need to inspect and pack your stuff. There are certain items (like knives) that are prohibited. Take the stuff to the China Post office for them to box, or you can buy boxes ahead of time (for 11 RMB) and don't tape them shut.
2) Take a friend who speaks and writes Chinese with you. The staff usually speaks little English and the forms require some Chinese information.
3) Create big "To"/"From" address labels in your destination country language, for your packages. This is a simple precaution to take, in case the China Post label is lost, damaged, or illegible for the postal workers in your country. Either attach them to your boxes beforehand, or take them (along with a roll of clear packing tape) to the China Post. After they pack your box, they will allow you to attach it. (Note: Take your own clear tape.) Use the tape to cover the entire surface of the label.
4) Be prepared for some strange objections to what you send. For some reason, you can't send knives of any kind. They kicked out my scissors, kitchen knife, and pocket knife. For some reason, they didn't let me send my Brother P-Touch labeler, or the refill tapes. They also get a bit nervous with anything that looks like medication. (In my case, they let me send most of the stuff I had.)
Here are some helpful links: