Hi Folks -
I just pulled the trigger on a used D7000 with the 18 to 105mm lens for $530 (fair price, I say). There was enough in the budget left over to pick up a speedlight, as well...
The kit cost $92, so for under $650, I got a nice set up, I should think. In a bit, I'll start looking at some wide-angle lenses to play with (I used one of these when I was in Alaska, which was quite nice).
Thanks to everyone that provided input/advice/hand holding!