There are two things that make technology cheap: software and quantity. Unfortunately, those two things are absent from cine lenses.
When you write a program, your costs of making one, a thousand, or a million copies are virtually the same (and virtually zero). This is just not the case with hardware. Cine lenses are basically all manual, and there's just no replacement for fabricating extremely high quality mechanics and optics, with an all-metal constructions that's a couple steps above the best still lenses.
If it was easy to make a lens like this for $5K, someone would've gotten up and do it. Tokina can't, Nikon passed, and Canon opted for the same price level.
A 28-80mm f2.8 (T2.9) is considered a 'classic' cine zoom lens, and there have been dramatic price cuts over the past 2 years. Just a few years back, the cheapest option for the above was the Angenieux Optimo, for $65K. You could settle for the newer DP Rouge 30-80mm for a mere $42K, then just last year Fujinon announced their 29-90mm for $38K. This is why the $20K price point for this Zeiss is news. You can't compare it with a Canon L because you can't do with an L what you do with those lenses.
BTW, the CZ name isn't for Carl Zeiss - it's for Compact Zoom. It compliments Zeiss' CP (Compact Prime) line of entry-level cine lenses.
My company was looking to acquire our own cinematography package, and after months of research (and 10 years in the film/TV business) I recommended a $12,000 cinevised Zeiss prime set and a $700 Panasonic GH2. We're happy with the purchase and the value it brought us, and that includes my boss.
It is rather pointless of DPR to post these. These lenses are strictly for cine use, and a complete waste of money for stills (get a Canon L). Motion picture has a completely different set of needs by virtue of taking 24 (or more) exposures per second and projecting them successively. Manual focus, aperture pulls, focus tracking, breathing, internal focusing, consistent aperture... all those things are rather pointless in stills and critical in movies.