KevinR said:
"I am not gentle with my gear"
and THAT is why I would be VERY careful when buying a second hand Nikon.
They were always considered as being the true professional's workhorse, and their reputation was closely rivalled by that of the best Canons. But in most cases, it might even been the case that either of the 2 brands will have taken many times as many shots as a top "amateur" camera, and the Nikons may have been to some horrendous environments, deserts, mines, arctic conditions. the list is endless.
Top non-pro cameras will probably have been lovingly tended by wannabees, taken far less shots, and rarely been anywhere extreme.
I suggest you look for the better models in the "lesser" marques - I am thinking of Olympus, Pentax, and Minolta especially. I am biased, maybe, as I have recently bought 2! Minolta strove with all their might to make that credibility leap into professional acceptance, decades ago when I was last keen on photography. I don't think they ever quite made it, I doubt if they have yet, but in their efforts they created some stunning cameras and lenses. See the Rokkorfiles.
In the late 60s and early 70s I worked in a camera shop, selling mainly Pentaxes and Chinons, and my interest survived until Olympus slrs started to appear. I think Pentaxes and Olympusses may be very common, But I was never impressed with the build of the cameras - they all seemed too light and frail. The Pentaxes seemed tinny, and the Olympus plasticky. All this at a time when plastics were (maybe) not as good as nowadays.
Soooo, get a Minolta. My X300 cost me 45 dollars, complete with f1.7 50mm. My second is a black plastic X300s with a 100-200 lens, a 24-70 vivitar lens, a dedicated flashgun, and other sundries. That lot cost me 100 dollars. I dislike the black plastic of the X300s, but it is cladding for a steel body I believe.
I couldnt afford a Nikon, even though it may well have been harder worked, The Minoltas are both near mint, and in PERFECT working order.