Just replaced my D90 which was stolen with another D90. The D7000 is I'm sure an excellent camera, but not sure if I'd be just paying for "the latest" kit, without fully utilising the older stuff yet!
The D90 covers everything I need, there are plenty about and plenty of good books to make learning how to use it easy. Also plenty of deals to be had.
As above, re: prices. I just paid £450 used, which I felt was pretty good value, as I hadn't seen any cheaper than that. Good kit lens in the 18-105, certainly sets you off well!