Don't be fooled- many photographers that need more resolution than 12mp (no matter how you slice it, 12mp is NOT a lot of resolution for large high quality detailed photo prints..) and who either can't afford the high price of medium format camera, back, plus lenses costing $4,000 each, have purchased the D3x. Expensive? The answer to that question would be relative to what? Relative to a medium format system (camera, lens, and digital back) then the D3x is a much cheaper alternative, especially since most pros already have the bread and butter lenses already in their possession...
Hmm.. doing a little basic math tells us that the typical professional Nikon shooter actually spends less money buying the D3x, and gets a better camera, compared to establishing a new kit with the Canon 5d2.
Let's put things into perspective, the 1ds3 is still over $6,000 while its younger sibling (5d mark 2) is less than half that price. Justified? To those that feel a more robust body and more capable and dependable focus system is "worth it".. then it's worth it. When the D3x debuted, it seems people forgot that the Canon 1ds3 was about $7,000.
I think if (many) photographers complaining about the price did a cost to (short term) return-on-investment analysis, the D3x winds up not being as expensive as one may think at first glance.
.. Of course if you're not printing large landscapes, fashion/glamour/beauty, portraits, etc.. then the price of the D3x is merely moot chatter and not a serious concern.
Best in photography to everyone