Pricing all depends on how Sigma wants to position the lens in the market place.
If this has the IQ comparable to the Otus (obviously can't be better than $4000 lens), and they price this under $600, they can COMPLETELY CORNER the market on 50mm primes. In fact, it can very well be the most popular lens available.
There is no way, Canon or Nikon will compete at the same price point.
On the other hand, they can easily sell it at what it is worth on the market, which would be around $1000.
(24Lii, sigma 50A, 135L), and for the other ends of the spectrum, sigmaEX 14mm2.8 and sigmaEX 100-300F4.

