My take with Nikon:
Nikon D800 or even slightly better
D800E (~$1300 used)
Tamron 15-30mm f2.8 VC (~$900, ~$800 used) or
Nikkor AF-S 20mm f1.8 (~$800, ~$600 used)
Tokina 100mm f2.8 macro (~$400)
AF 60mm f2.8 micro (~$250 used) or if you got the AF-S 20mm f1.8 then maybe you'll prefer
AF 35mm f2 (~$250 used) as a walkaround
[Flash]
SB800 (~$150 used)
When I only give used prices that means you cant get that stuff new anymore. Obviously used prices arent reliable.
The two last entries are just for filling the budget up. Either way they are both excellent. And you probably really want a flash for macro.
Not happy with having to pick the D800 because the D810 was such a sweet upgrade which really addressed a lot of issues with the original. The D800 is a really good camera though and its optimal for both landscape and macro.
A used Canon 5D Mark II is probably inside the budget, too, maybe even a 6D. Obviously this means only the offbrand lenses alone, or possibly some Canon stuff I dont know enough about.
Dont know if the Tokina 100 is also better than Canon middle macros. Nikon has two awesome macro lenses (AF 60mm f2.8 micro and AF 200mm f4 micro), the middle one is also okay but not as good as the Tokina. The Tokina is also a really good portraiture lens. The new internal focus (all AF lenses are screwdrive lenses and make a slight sound when focusing, because the motor in the camera is driving the lens, while AF-S lenses have an internal motor and are basically completely silent) ones are mostly just more expensive, but not optically better (rather inferior, actually).
That should just about take care of your $3,000.
Well, yeah, it would do THAT.
But:
Its not full frame. The OP already has an APS-C system, he wants to upgrade to full frame (I think ?). Also the really good wide angle glas is only available with full frame and since thats the prime thing about landscape, so thats definitely what I would go for.
The only reason to get a D7200 over a much cheaper D7100 would be the buffer, but the OP wants to do mainly landscape and macro, thus he doesnt need the bigger buffer, so why the frak do you waste money for getting him the D7200 ?
Otherwise you give him a low quality poor build quality hella overpriced convenience zoom, and OK macro (but its not as good as the Tokina, its kinda dark and its not compatible with full frame either, none of these lenses is) and the worst of all Nikon telezoom options (the 55-200 is much cheaper, the 70-300 would be the optical best and is the first thats really good with sports).
Quite frankly I think your suggestions are horrible. You waste the OPs money, not spent it wisely.
refurbished 6D or used 5D3 and some nice "L" lens should take of your $3,000
Which is actually one of the reasons I dont like Canon too much. To get high quality with Canon, you're supposed to buy expensive "L" lenses. Otherwise you dont get the same tight tolerances. Nikon, Fuji, Leica, Pentax etc dont do that. Even the cheap plastic Fuji or Nikon lenses have the same optical quality as the expensive glas.
If macro is your main interest then Canon might be worth sticking with for their unique MPE 65mm f2.8 macro lens.
You can get the same thing with Nikon and the PB-6 (or some compareable) plus the AF 60mm f2.8 (or one of the fully manual predecessors). The new AF-S wouldnt work because it lacks the ability to control the aperture without a camera and the PB-6 is "dumb".