I am shopping for a new scope and I want a 50 mm objective lens and I came across this:Zeiss Terra 3X 4-12x50mm Riflescope w/ Plex Reticle, Matte Black 522741-9920-000. I always thought Zeiss scopes were much more expensive than the 450 they are asking for this one and I dont know what the 3x in front of the 4-12 means. Any opinions on this scope or something in the same price range that would work for me?