Another $100 and you can get an Eotech which is what I run they are very durable and waterproof. I have been looking at the Aimpoint Micro but it way to expensive or my blood. But the Eotech I have honestly has taken a beating and still functions like the day I got her. There are so many options out there just remember you get what you pay for.
https://www.primaryarms.com/EOTech_s/585.htm Check this out, the 512s are out of stock but I've heard that magnifier is really good and its free. I'm actually thinking for that price checking out the magnifier and mount separate since I already own the 512.
If you don't want to spend $400 and get an aimpoint pro, I'd suggest checking out the vortex strikefire. It has a screw on 2x magnifier, seems very solid, several green and red settings, and runs about $170
That or check out the vector stinger and a clone of the aimpoint 3x flip to the side magnifer. The vector runs about $50 and the flip to the side clones run about $75
Another option I would recommend would be a Bushnell TRS-25. I had one on my AK and ran at least 500 rnds and it stayed zero'd. They run about 80$ to 120$ on the net. Both eyes open worked very well. A bit bigger than an aim point but quite a bit less $$$.