I've had nearly all the Nikons D60-70-80-100-200-300-D2x.
The best bang for the buck is the D200 right now, $450 or the D70 for $250-$300. The D100-200-300 viewfinders are better than the D60-70-80-90 finders. The best value zoom is the $150 18-70/3.5-4.5 AFS. The $100 50/1.8 is a great lens, as are the 35/2 and 24/2.8 AF lenses, you don't need the "D" versions.
Me? I've always liked the more robust semi-pro bodies but realistically the plastic bodies and lenses are very robust. And the D200-300 are quite heavy for a walk around camera... So I'm getting a D60 ($400 usd) w the new $200 35/1.8 next month. For what it is, it is great as a compact, easy to carry camera that is a step up from the Canons and Panasonics, maybe not in feature count but in usability. The Nikon files are better too I think, more range than everyone else other than Fuji and some Canons. If I find that I need a wide angle lens for a project, the cheap 18-70 or 18-55 AFS lenses are great bargains.
I had the $$$ 28/1.4 once and compared it to the cheap 35/2 and was amazed that a $200 lens was as good at f/2.... so don't belittle the cheap little Nikon primes.
As for full-frame, it is a nice idea but I wouldn't bother unless I could drop $2200 on a D700. The old Kodak 14n was only good at ISO 80 and it was based on the N80 plastic body -- so the build quality isn't any better than a D40-D60. It's no longer supported and it has a really checkered reputation.
The D2h is a great camera but it will break your back, it is a pig....
If you really want FF, look for a beat up Canon 5D, which might be almost down to $800 if the seller is desperate. But the build quality of the 5D is shoddy compared to the cheap Nikons, so any bargains should be carefully inspected.
