Best bet IMO would be to get hold of a bike box from somewhere like Halfords and ship it in that. The volume of that would be pretty small so the cost would be reasonable.
Food for thought.
The £75 I quoted was based on a Halfords 71cm x 144cm x 25cm box. One should also consider whether these boxes are man enough to protect a bike when it is containerised with dozens of 80kg BB boxes. Halfords bikes are the only items shipped in their containers