Tom Caldwell: Just think of the primes as limited editions (prototypes?) for some as yet unannounced "stills" camera for the masses. Interesting that not only can they be focused manually but they have manual aperture control and will suit a FF sensor. This is a major departure from the current EF electronically controlled aperture. Is Canon about to obsolete it's current EF range of lenses? - hardly dare one might think.
Pricing? Adjust demand to cover the hand assembly of very specialist lenses which would never be expected to sell in any quantity. Too big a demand? They will put the price up.
they are EF mount not PL. Their new cine cameras come in 2 flavors PL or EF.