The AF-P 10-20mm Nikkor is a bargain lens at just over $300... if you can make it work on your camera (
https://www.nikonimgsupport.com/eu/BV_article?articleNo=000035705&configured=1&lang=en_GB). It is one of the few ultrawides with image stabilization (which may not be all that big a deal on an ultrawide... short focal lengths are pretty easily handheld, after all).
The Nikkor AF-S 10-24mm and AF-S 12-24mm are very good, but vastly overpriced. They are the most expensive ultrawides on the market, by a wide margin.
The Tokina AT-X 12-28mm f/4 DX and AT-X 11-20mm f/2.8 DX are much more affordable and darned nice lenses. These are the "latest and greatest" and improved on earlier versions (below). The 11-20mm has gotten a lot bigger and heavier, now uses an 82mm filter.
Older Tokina 12-24mm f/4 and 11-16mm f/2.8 came in two versions. In Nikon mount the first version of them is "motorless"... that's okay on D7100 or D500 (but those lenses will not be able to autofocus on D3000-series and D5000-series, among others). The "II" versions of both those lenses are little different, EXCEPT that in Nikon mount they had the in-lens focus motor added. 11-16mm is sharp... but extremely prone to flare and has a very limited range of focal lengths. 12-24mm is almost as sharp, much less susceptible to flare, but can show some chromatic aberration. The newer models (11-20mm and 12-28mm above) that superseded them address a lot of the short-comings of the first two versions.
All Tokina use a "focus clutch" mechanism and those with in-lens motors use a micro motor. Not the fastest... but not really a problem with an ultrawide which doesn't have to move the focus group very far anyway. The focus clutch arrangement makes it impossible to do "manual override" of AF... you have to first shift the lens into MF mode (slide the focus ring). When set to AF, the focus ring is disengaged and does nothing (a protection for micro motor type focus drives). Otherwise, Tokina are well made, nice lenses. Tokina lenses use the same DX and FX designations as Nikon... they also rotate their focus and zoom rings the same direction as Nikkors (opposite Canon and some others).
Only you can say whether you need f/2.8 on an ultrawide or not. Most people don't... we generally are stopping those types of lenses down, not using them anywhere near that large an aperture. But if you do a lot of night photography or photojournalism or sports... it might be useful.
Tamron 10-24mm in the latest version is the only other ultrawide available for use on Nikon that has image stabilization (VC). It's also relatively affordable and replaced and earlier model that lacked VC.
Sigma offers a 10-20mm f/3.5 that's fairly big and heavy, but has come way, way down in price. They used to offer a smaller, lighter 10-20mm with a variable aperture, but that's been discontinued so can only be found used now.
Sigma also offers an 8-16mm... the widest of the ultrawides. It goes where no other lens can, but has fairly strong wide angle distortions and a protruding/convex front element prevents using standard filters on it.
They also have a 12-24mm... but it's actually a full frame (FX) lens and would work out to be very expensive just to use it on a DX camera. There are DX lens options ("DC" in Sigma, "Di II" in Tamron, "DX" in Tokina) that are a lot smaller, lighter and considerably less expensive. The Sigma 12-24mm also has a protruding, convex front element that precludes using standard filters on it.