As a big fan of 12 x 50 glass I am saving up gold nuggets for new Swarovski bino. Have owned Swaro 8 x 30s for decades but bigger have been Ziess and now well beat up. I am set on 12 x 50s but as i shop em I always wonder why Swaro 15 x 50s are universally cheaper than 12 x 50 Swarovski ? I guess it is what it is - but just wondering ?