Probably no use, but may be worth asking McMillans airfreight services 01753-68911.
If you can deliver into their offices near Heathrow, and pick up form the other end, it should cost more than (im guessing) around £350 incl everything.
Ask them to quote for accepting delivery, ptting it on a pallet and shrinkwrapping it (a 120cm x 100cm standard pallet) and then aiirfrieghting to the overseas airport.
This post is probably no good, but the price of £765 seems very expenive to me so just giving an option which may or may not be any good.