I would normally agree with everyone that glass comes before body, but I have to weigh in on the D80. I absolutely hated my D80. Looking back on my D80 photos tonight, it amazes me how exposure and color were completely 'off' with that camera. I also notice a lot of focus inaccuracy and soft shots from my D80 photos. I always shoot RAW and the RAW files from the D80 require so much post-processing it used to make my head spin. I've owned a bunch of Nikon bodies and the D80 was hands down the worst. I loved the D50 so much I bought another after regretting selling my first. I briefly owned a D90 as a backup for my D300 but sold it to upgrade to a D800. Every one of these bodies made the D80 look like a bum camera.
So, I'd highly highly recommend getting rid of the D80 and moving to a better body. You won't regret it.