The trouble with visiting Thailand is everything is so cheap ! It always seems difficult to fit all that stuff in your bags.
The best solution is to wander down to a post office, ( franchised post shops don't sell the bigger cartons) buy a carton the size you need and send it home. As an example, 15 kilograms to Australia using SAL (economy air) is about 3600 baht and takes about 2 weeks. For smaller items you can use air mail or EMS international couriers. For larger items you can use surface mail which we're told takes around 3 months. Should you wish to ship through shipping agents and you're willing to pay for all the paperwork, a square metre will cost you around AUD$100 plus insurance or around USD$80.
Check the links page for the Thailand Post pricing wizard.
