I have a feeling the target audience for DVC purchases at Aulani would be more Japan and Australia and not the mainland US.
Japan is an important market but don't discount US buyers.
In 2010 there were 6.98 million visitors who arrived by air. Of those 1.24 million came from Japan. About 17%.
By comparison, 2.96 million were from the western US and 1.63 million from the eastern US.
Hawaii is a very popular vacation destination for those on the west coast. And the west coast is also a big growth market for DVC. As of 2009 they claimed that 85% of all DVC members lived in the eastern US. So DVC can appeal to a lot of non-members living out west by stressing Aulani,
Disneyland resorts (including use of points at DLH and PP) and the occasional trip to Walt Disney World.
With regard to Japan and other countries, the exchange rate is very favorable right now so that helps with the initial buy-in. (Could also be a reason there's been talk of DVC offering some means of pre-paying dues several years in advance.)
I'm not surprised at the 33% variance. If it was going to be a low number, Disney could have corrected the situation over a couple of years with relatively modest increases.
As for the annual costs, dues alone it would run $2400 for BLT MK View Two Bedroom during Premier season. $2600 for the same room at Grand Californian. Really it should come as no surprise that Hawaii is more expensive...particularly with the more elaborate amenities.