[Rover]

So, we now expect a Tokina to be the same price as a stop faster and much more glass containing Sigma Art lens? Or be more expensive than a faster Nikkor?

If you're surprised about the surprisingly way too bold pricing, don't be: after all, many manufacturers thrive on this kind of thing... sometimes crossing the border way into the realm of daftness.

Tokina, after all, is at least a competent manufacturer, and their example is a rather benign one. Besides, both the Nikkor and the Sigma come with some inherent caveats, the lack of which may be a value adding proposition for many.