It hit me today, I really don't need the 24MP D7100 to replace a D50. I'm after dynamic range, and the D7000 has that. I'd like to keep some resolution when I crop, and the D7000's 14MP will let me do that. Then, Amazon lowered their price for the D7000 to $484 - That's It!!! I sweet-talked my loving wife (it might help that she's semi-delirious with something flu-like) and she ordered it on her Amazon account.
With no current aspirations past doing some train photography, this investment just made sense.