Comparing a Vortex Crossfire II and a Nikon Buckmaster or P-Series, glass is significantly better on the Nikons.
Nikon probably did decent sales in the $100-$200 range, but not anywhere else. They sort of adapted and re-imaged the brand too late-tactical, exposed turrets style.
M-Series and Black (not that the scopes were terrible) were a major flop
The Crossfire II line is the cheapest available from Vortex, but you’re completely ignoring the Diamondback line.