I have one of these for sale, new, in the original unopened package.
(https://www.specshop.pl/eng_pl_Holosun-HS403GL-Red-Dot-Sight-Low-mount-1-3-Co-witness-Mount-15791_1.jpg)
http://www.trueaim.fi/verkkokauppa/index.php?main_page=product_info&cPath=72_104_311&products_id=1332&zenid=ju0p56h9dcj3c2qpgnf5t6ie06
185 euros, shipping included.