I've used Trijicon MRO's on several AR-9's and they have held up well over thousands of rounds. But they are more like $400.

For a bargain optic, I've used the Primary Arms Advanced Micro Dot on a few rifles. They are cheap - around $150 or less and have performed well for me.

The only Holosun I have is on a Sig P365XL. It's the small one like a SIG Romeo Zero, and works fine but seems to have a little distortion/magnification.