I read somewhere that a large percentage the 2013 LR4s are being bought up and exported.
This is a similar event that happened to the previous generation of RR and RRS. Because of the unique combination of features, the V8, and most of the "bugs" being worked out. The North American versions became highly sought after. Guys are buying them up at auction and from dealers and sending them elsewhere because the V8 was not a very common option.
I am in a similar boat with my next Land Rover (I am never getting rid of my LR4).
I want a RRS SCV8, Dynamic, with a third row, and rear climate package. While I wont argue the usefulness of the 3rd row in a RRS, it is a minimum request from my wife (we all know how that goes). I have not had much luck finding the color I want, with the features I want. But it will happen eventually. Took me about 8 months to get my current LR4, available locally.