You did get a great deal on an amazing camera. As already stated the newer SD cards where not rated with the D80 they came out long after. Which is a good thing for you because the older SDHC are cheaper.
The D80 is a fine camera. Wish i still had mine as a back up. One tip i can give you is some D80's tended to overexpose by about a stop. So this could be something to look for. And you can set your exposure compensation to mitigate this if you find it a problem.