Haven´t sent from Oz to South America, but I´ve sent from Sydney to Helsinki by sea, and it was estimated to take 42 days (faster than I´d expected)... but then there were some delays on the way, and so I ended up being without the bike for about 60 days.
Seafreight is slow. But 80 days to get your bike across the Pacific... that really sounds a bit long to me. The actual sailing would probably take about 20-30 days. But of course will also depend on the routing.
On longer distances you might actually save a bit, if you can wait for the vehicle to be sent by sea (but it also seems common, that by sea, you get those delays).