Gday,
pends how much you are going to send.Parcel Post will pick up from you ,but you have to meet the contract agreements. There is also a minimum amount ( Ithink about 5k) in order for them to pick it up. Problem with post is that international shipping you will only get small discounts,if any. But it is very reliable, safe and fast and competitve to other carriers. You can also try DHL.
International shipping prices from here are pretty horrendous as well! Unless you are shipping huge amounts, sending one shirt will bite big time. I sent a pair of shoes to Hong Kong= $28!
Just try and get a contract, the sales reps will treat you like royalty and you can persuade them big time
Cheers
ps also try and not send the shirt in one of those pre paid satchels...they sometimes get caught and destroyed in the sorting machines...just my experience
