The guys at Dakar are very helpful. Personally I only used them on the return leg as I organised my own shipping outbound, but I am sure they have plenty of experience bring in too.
In a few words: fly it, don't boat it.
More reliable, more predictable price-wise and more convenient.
Also, to get costs down, see if you can dismantle the bike at the craters. Small the bike is packed the cheaper. 20cm off the height, or 15cm of the length can make huge difference to your volumetric weight, on which the airfreight is calculated.
Adventure: it's an experience, not a style!
(so ride what you like, but ride it somewhere new!)