The one optic I have that meets your criteria, and that I actually use, is the Millett Zoom Dot 30mm red dot sight. It can be had for less than $300 if you look around and also somes with (at no extra charge) a very nice picatinny/weaver mount that cowitnesses perfectly with my AR (some places try to charge extra for this mount & the covers, but it is now included in the package, so call and check). It also comes with lens covers. It's solid, still made in the USA, and the dot is variable between 1 moa and 10 moa. It's a 1x reflex and works as well as any of the others I have used. No complaints other than it doesn't use a AA battery.
Some don't like that it is an "auto-adjust" dot but I've yet to find a situation where it doesn't work correctly (dark to bright and vice versa).. Cheers