If you don't mind 2 stops it's $790 with air canada. Try searching with momondo.
Be aware booking with the cruiseline does not give any gaurantees beyond going through the airline. If you miss the ship due to plane being late it's not the cruiselines fault, they simply offer the service to book through them and sometimes get a discount for the volume.
11 cruises in 2012, 90 nights at sea visiting 15 countries
8 cruises in 2013, 56 nights at sea visiting 7 countries
Next cruise: None scheduled
PM me if you need a cruisemate for any Europe, transatlantic, or Panama Canal cruises
Date, ship, cost pp