Perhaps the Aikikai should take this into consideration?: there must be significant differences in the cost of living, from country to country; so much so that in certain countries, only the rich few can afford to pursue, and progress in, aikido.
And that has to be a barrier to its propagation.
It certainly is, Graham. Every year we have a few students who beg off from the dan exams for financial reasons. Some dojos and teachers choose to help out with loans to ease the burden.
For the last few years, I've been the designated representative of my federation in dealing with Hombu on exam fees. So the effect of the high cost of dan promotions is something I see quite a bit of.