Hi Mick,
Well firstly I've never done it so can't give first hand comments.
I've had many friends shipping by container (various sizes) and I would call it expensive but it all depends how important it is to ship a whole container load of stuff.
For me I've decided to use Balikbayan Box shipper like LBC for most of the smaller stuff and a shipping organisation to handle any larger stuff that needs individual attention or special packing.
May I suggest you
take a look here for an idea. Please have a look at the video to see how the packing can be managed.
The cost is very simply based on the final volume of the items when packaged.
It really does depend on what you want them to do, but in principle just on volume it's not much more expensive than the same volume of Balikbayan Boxes.
If you click their 'Get a Quote' selection in the blue bar at the top of the page you can estimate your own volumes.
Anyway hope that you'll find it helpful