If you take it to the counter at Canada post, you may get a better quote. Where are you? We have a shipment going soon out of L.A. in a container...but it takes a long time.
As I stated in my e-mail to you. I am currently looking into the same thing and have found that Greyhound Express Booklet quotes $219.08 for 28lbs to Australia. You would have to confirm this price with them.