In my experience, anyone with any kind of physics background thinks that Braille displays could be radically cheaper.
Anyone who spends a couple hours on researching the problem thinks that the price could be improved, maybe by half, but that the problem isn't as easy as it seems.
Anyone who tries building one eventually arrives at the conclusion that making it cheaper requires a bunch of tradeoffs which they're not willing to make.
As far as I know, the central problem off Braille Display engineering isn't making the dots, but putting them so close to each other. If the gap between dots would be half an inch, let's say, a braille display would probably be a hundred-dollar affair. It would be completely unusable for any kind of reading, though.
Orbit Research managed to find a way to make Braille displays somewhat cheaper, which is now incorporated into the Orbit Reader 20 and 40, but that technology has a much slower refresh rate than traditional Braille displays and causes them to be much louder.