I guess there are a few factors to consider. But if 16mp, scene modes, and movie mode are not on you requirement list then the D300 is appearing on the used market now. The D300's has been out long enough now so it will be harder to find new. Just checked Grays of Westminster and they have one for £789 with one years warranty. They are also currently doing the D300's for £999 so its cheaper than the D7000.
Grays took on their grading system from Peter Walnes who I dealt with years ago, and from my dealings with them, and I have bought quite a few things, I have never been dissapointed.
Don