Is a nikon D80 still a good dslr considering its age and likely amount of clicks?

Does the camera indicate the number of clicks in its menu? I'm looking to trade a pro guitar rig for a good dslr and i have an offer for a D80. I'm just wondering if its worth it considering the D80 arrived on the market in 2006?

Depends on what you want to do with it. It was a decent camera at the time but the D90 was a lot better.

What's the approximate value of that rig on ebay or craigslist?

On any nikon you can get a shutter count by examining an unaltered jpg file with an exif viewer such as opanda. This is reliable since the count can only be reset with special nikon service software and that is just not available on the internet (believe me, I looked)

Yes, if it is in good condition, it is still a very good camera. As for the worth of the camera against your guitar, it will depend on not only the camera body itself, but what else there's with the camera, such as lens(es) and the like.

There's no simple way to find out the number of shutter actuations that I know of, but that doesn't mean it can't be done. Hopefully someone more familiar with the D80 can answer that for you.