That is a very good point and the main reason that I have not bought a D600. My favorite lens is my 17-55mm f2.8 DX and I don't think the D600 kit lens is nearly as good as the 17-55mm. I also have a Nikon 12-24mm F/4 DX that I would have to replace. Once I start adding up the cost of lenses, switching to FX becomes very expensive. But it is very tempting.