This is a myth that people keep repeating. E-ink prices have very little to do with patents.
E-ink displays are more expensive because they are utterly niche compared to LCD screens (there are over 6 billion smartphone users in the world right now, and plenty of people own a smartphone, laptop, desktop, TV, tablet, smartwatch, then use a computer at work, interact with a self-checkout kiosk at the supermarket, etc).
There are basically two common use-cases for e-ink right now: e-readers (and nowadays 'e-notes', which have stylus input), and smart-pricetags in supermarkets. Neither of these require large e-ink screens, so there's no existing production line to feed these 32" monitors off. The 32" screens are created by hand-fusing 4 16" screens together, IIRC. This isn't automated because there's not enough demand to automate it.
The reason there's no demand for e-ink screens is that the technology just isn't very useful - I love e-ink, but it's not particularly flexible and can't be used in general-purpose devices that need to display video. It has its niches, but they're niche.
It's lower battery usage is due to low refresh rate, which is inherently incompatible with displaying video -if an e-reader refreshes once per minute and an LCD screen would have to refresh 60 times a second, then the LCD needs to refresh 3600x more often which means e-ink saves power even if the e-ink screen takes 10x or 100x the power per refresh. But if the e-ink screen plays video at 60FPS, then by definition it's refreshing 60 times a second and thus will use 10x or 100x the power of the equivalent LCD screen playing the same video.
If we want prices to drop substantially, we need more use-cases for e-ink. There's hope here, as the recent fast-ACEP tech (the Gallery 3) is color-tech that doesn't sacrifice half of your contrast and resolution (like Color Filter Arrays do), but is fast enough for an interactive device and is almost as fast to refresh as a monochrome screen (previous ACEP screens took min 7 seconds to refresh the screen, the new tech is amazing). With some refinement, it might be enough to bring e-notes somewhat into the mainstream.
So, all that said: e-ink screens that are 6" or less aren't really any more expensive than an LCD. It's only when you get outside of normal e-reader sizes that the price goes up like crazy.
...not to mention, e-ink isn't the only "e-paper" company - ReInkstone are making their DES screens, which dodge at least some of the patents on microencapsulated electrophoretic displays as their cofferdam tech doesn't use microcapsules at all and instead integrate the seals into the display.