I wish they would make defective units available at a lower price. I don't mind some stuck pixels if it means I can get the reader half off.

I think you're being too optimistic about the discount to defect ratio.

What happens to a defective unit? Is it disassembled with the base components put back in the assembly line? Or is it just sent to the landfill? I suppose OP was assuming defective units are just trashed.

That's not the way the economics works. If they sell you a half price unit with a defect, they have potentially lost a sale at full price. So they don't.

"Now some 13 inch models even accept video input, so you can potentially use it as a terminal / PDF screen."

Do you have a link/suggestions for a device? I've been wanting an eink monitor for text tasks for years (I'm not a gamer).

You might look at the discussions of the Boox devices on the mobileread forums https://www.mobileread.com/forums/forumdisplay.php?f=220

I've not gone through them recently but there are some things that sounded like that when I was on there a few months ago.

It's probably also partially an economies of scale thing. Amazon used to sell a 10 inch version of the Kindle but discontinued it due to poor sales.

I bought the Kindle DX when I was in a masters program. I loved the screen. I did not love the PDF rendering speed. At times it could take several minutes to turn the page on a PDF.

Basically, any PDF that had vector-based statistical plots would bring the poor thing to its knees. I wished at the time that there were a large screen PDF reader with modest computational umpf.

Nowadays, it sounds like the Sony reader is great, but costly and the Remarkable reader wasn’t vaporware after all... but it’s similarly costly. $350 feels like the right price to pay for such a device. I have no idea if that price makes them worth manufacturing.

These days the Calibre project embeds a number of great conversion projects and adds its own valuable conversion contributions to turn PDFs to e-reader formats and still do a decent job of preserving layout (a ways to go to match Acrobat's conversion of PDF to MS-Word, but steadily getting there). Take a look at how it manages with your selection of PDFs, and see if they work better on your DX if you still have it hanging around.

Any links/examples to the 13-inch models, please?

Which models?