Never underestimate the collectors!
I'm buying 7 other formats. But I'm not buying that one, as it simply does not have anything in it that appeals to me, especially when the other boxset also has the only relevant content, the bluray, and I agree with you that even the "cheaper" box is over-priced for what it contains.
Reading the official forum, the posters there seem to be in no doubt that it will sell out, and it's getting a bit panicky. Maybe I'm seriously underestimating saying they'll struggle to sell 200, but I genuinely can't see there being 2,000 people with €400 to drop on the box, considering the multitude of other formats that are more relevent to music fans than samurai trinkets and origami and the likes? Surely buy the LP, CD book or regular boxset instead.