You may be disappointed down the road. There are aspects that you will see later that are masked by the novelty of a huge angle of view. I would rent and not buy one as others have suggested. Or buy used, so that you won't take such a hit when you sell it later.

There is the "honeymoon factor" that happens after purchase - one can't seem to get enough of the ultra wide point of view. For a bunch of weeks one leaves the lens on the camera and shoots everything with it - exploring a novel and very different perspective. Then the honeymoon is over, almost as quickly as it appears. The ultra wide perspective together with the extension distortion, volume anamorphosis, barrel distortion, CA, flare (in some cases), and on smaller sensor cameras (<full frame), distant details get "mushed" together, so a stand of trees looks fake, as if the leaves were painted with a broad brush. At more or less normal viewing distances one might not notice, but up close it is hard to ignore.

I'm not saying that a 10mm lens on a cropped sensor camera or a 14mm lens on a full frame camera is automatically a bad thing. I've used both. They can lend an interesting point of view where there is sky or interesting foreground elements involved. But to keep verticals vertical, one must keep the camera level. If you tilt the camera up to minimize foreground for a more interesting composition, or to capture more sky, then verticals begin to converge - which is referred to as keystoning.

There are only two solutions to this and both involve loss of pixels and or image width. First one can correct this "keystone" effect by applying adjustments in post processing. Doing so involves expanding the top of an image, which often ends up reducing height and overall horizontal angle of view. The other solution involves keeping the camera level and cropping the top and/or bottom of the image for compositional considerations.

All too often, at least at first, the old adage that when the only tool in the toolbox is a hammer the tendency is to treat everything like a nail. Maslow and other behaviorists describe this cognitive bias as "the law of the instrument" - an "over-reliance on a familiar", or in this case a new, tool. Ultra-wide lenses are actually highly specialized tools, and only appropriate in a handful of situations.

If standing on a roadside viewpoint or a ledge trying to take a picture of a mountain range, the last tool I would reach for would be an ultra-wide lens.

It is commonplace among experienced landscape photographers using digital cameras to go in the opposite direction - to use a longer lens and stitch a panorama. This is a good article that shows how to get that "ultra wide" view without an ultra wide lens. Pretty much every "unique" and sometimes undesirable characteristic of wide and very wide angle lenses is eliminated. It shows that even a tripod is not necessary to do panorama shooting - all that is necessary is to ensure that you have as many images you need to capture the scene, overlapping at least 1/3 of the image next to it. I generally use 1/2.

https://petapixel.com/2016/10/27/stitching-panorama-forget-wide-angle-lens-home/

These discussions are always interesting. What's also interesting, though, is to do a quick search of the literally hundreds if not thousands of barely used ultrawide lenses. Tons of folks think they need one until they get it and find out that they really don't.

I have a 14-24mm f/2.8 zoom that I bought three years ago for night sky photography. I still use it for that and have also learned a couple of other things to do with it, but not landscapes. Things just get too small and too far away to be interesting, even when used with a D850, which has a lot of capability to resolve small details.

The suggestion above to rent an ultrawide first is a good one. If doing that just doesn't work for you, I'd suggest buying something economical like the Nikkor 10-20mm DX. It's not particularly fast, but it is a pretty neat $300 or so lens that will let you investigate what you want to do with it and make a more permanent choice later. If you don't end up using it, you aren't out a ton of cash.

Ultrawide photography is more than just sticking a short focal length lens on your camera. The difference between 18mm and 10mm on your camera is very significant. It introduces a whole array of challenges that you will need to learn to solve in order to get good results. It can be fun, but it's also quite a bit of work.

Have fun deciding, though. And let us know what you decide.