Don't think it hasn't crossed my mind.
In all honesty, I might choose to do it in a 4x4 instead, simply -- especially in central and eastern Africa -- it's just easier to get through with some additional wheels. That's OK; I have an expedition-prepped Uri (Namibian-built Toyota Land Cruiser derivative) sitting in my driveway too.
As for the additional €5000: film, duh. And mailers; I don't want to have to keep track of hundreds of rolls of exposed film over 15,000km of driving. Mail 'em to a trusted address for processing and archiving until I arrive.
I don't think asking banks for money is a winning proposition right now. :\