Look for freight forwarders in the yellow pages and ask a couple of them for quotes. I've used Icecorp Intl (604-273-9438) for the UK before I think. I know I've used them, just not sure if the UK part is right. Dimensions, actual weight, destination. They might be able to do better than most of the other options available, but it is hard to say when it is just a single box. With shipping outside of Canada, you do incur broker fees, value on the shipment, etc etc. You want to insure it, but not put a real high value on it because in the end, like here, there will no doubt be some sort of fees/taxes to pay. Find an option where you can pick up, do the customs clearance yourself rather than pay broker fees on the other side. Anyway, see if this is an option. The airline no doubt has much lower fees & incorporate it into the charges.
Savings usually happen when you have more stuff, then the price per box is lower than the price for just one. If the airline is offering it at 200, and everyone else is 400-800, I am not sure you will do better than going with the airline you are flying on lol.
DHL sometimes has sea options, maybe if you talk directly to a rep they would be able to give you cheaper options.
http://www.canuckabroad.com/forums/