I shipped a 58cm frame and fork to Australia. $297
The box was cut as small as possible, and the post office lady gave me a full 1" break on the restrictions.
The post office uses Fed Ex in Australia, or they did then.

The buyer did not like it, and as above, "quoted" much lower rates.
I adv he was more than welcome to bring hisself here and box and ship it himself, see if he could do it cheaper. In hindsight, I'd have kept that Merlin.

I've had this happen 3 times, all to Australia, and each time the buyer was adamant that shipping was reasonable.
Either they're misinformed, sneaky, or feel like money out of my pocket is negotiable.
Doesn't matter. I don't ship there.

On a much smaller scale, Canada can be the same way, but the buyers usually let you know up front, and I work to avoid Priority Mail, keep the packages small, and try to get it there reasonably. Even a Pay if Forward there can run pretty high...