How hard would it be to manual focus this lens?

So I have the opportunity to get a Nikon 70-300 lens in E+ condition for around $100. The only problem is, I'm a rather new photographer, and I have a D40, so this lens will not autofocus with my camera. My question is, how hard would it be to manual focus for landscape photography?

MF for landscapes is easy - they don't move

Very, very easy. Since landscapes don't go anywhere, it'll only take 2 seconds max to focus on it once you're used to the idea of manual focus.

If your shooting anything moving though, it'll be a lot harder to manual focus.

I shot this with a 300mm 2.8 manual focus lens. Once you get the focus down, it's pretty easy. After you do it long enough, you develop a "feel" for how much to turn focus for moving objects.

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I manually focus all my lenses. The 70-300 is a pain, to be honest. But for landscapes, easy… Why would it be difficult, they aren't going anywhere. But uh, 100$, is a tad pricey for a used 70-300. I bought a used one for 70.

As mentioned before, landscapes are easy since they don't move. You can just set your camera on the tripod and take your time in composing.also, most landscape photos are taken with a lot of light, making it even easier.