I was looking for something on Brownells and accidentally stumbled on Shield RMS with 4MOA dot for under $300. This is the exact red dot sight I have been using for several years and I have never seen it this low. My best guess is that they are clearing out their inventory as RMS 2.0 gets there. RMS 2.0 is a better sight, it seems (I have one of those as well), but for under $300 a UK-made RMS is mighty tempting.
The newer waterproof RMSw is also on sale, this time for about $100 off of what the normal price is. I took one of these (with 8MOA dot) on a 45Super Glock to Alaska’s bear country with me this past summer with a good amount of time spent getting splashed while in flat bottom boats going up rivers. It handled the water without any issues.