Trijicon RMR RM07 - adjustable LED, 6.5 MOA in like new condition, no box, $450
shipped or $425
if purchased together with the slide.
I also have a complete Glock 19 Gen 4 upper with slide milled for Trijicon RMR by L&M Precision (Mark Housel).
It has supressor sights installed.
It comes with both OEM Glock recoil spring and the "Super Heavy Tungsten recoil guide rod with spring".