digital or film?
with that budget in digital you're rather limited.
in film, that's another story. you can get a reliable manual body (any brand: you'll find a lot of posts with discussion on different brands and models, and even lists of the best manual bodies of every brand) for 50-70$. For landscapes and macros you can take all the time you need, so no need for AF or any other newer features; just a simple ol MF metal body.
Then, expend the rest on lenses. I would go for a 24 or 28mm for the landscapes and another of around 100mm with macro function
example: Nikon FM, plus Nikkor 28mm plus Nikkor 55mm micro. You could get to fit all that in around $200 (difficult but not impossible -and a real bargain, indeed).
a cheaper option: something like the FM, a nice 50mm and a ring to reverse the lens. That makes only less more than 100$ and could work as well