https://www.midwayusa.com/product/1009581380
This is the only one I know of and a bit more that 400. Maybe some site will give a code to get it closer to the 400.mark?
Eta: here a $499 model
https://www.leupold.com/vx-freedom-ar-3-9x40-illum-firedot-tri-mil-riflescope
Wow, what a course. Thanks for linking that Burdy. That was the most well written blog post I've read in some time. I felt like I was there sharing your frustrations and hindsight. I shot a sniper course and had some of the same, getting lost on my round count, not confrining zeros before going...