I am in Australia and already have the base game. I know I need all of the previous expansions as well (Which I'm willing to buy if I can actually figure out what else I need), but when it comes to the Taken King, everything either says "Not Available" or "Bundle Only". The only versions that are available to buy are the Digital Collectors Edition for $119.70 and the legendary edition for $99.95. Both of these contain the base game, which I already own, so if there's no option other than to pay extra to buy the game that I already own just to play the new content rather than just buy the addons, then they are going to miss out on a sale.
And I'm not the only one that feels this way.