The Boox Darwin is available in the Ectaco shop for $240 (or potentially lower; they have a "bid" option); the Caesar 4 is cheaper and the Poke 4 is more expensive. None of their other 6" models seem to be available in the US. (Unless I want to take my chances with ebay.)
The Hisense Hi Reader seems to be $400 and maybe only available through the GoodEReaderStore. Larger-but-narrower screen size might be okay. One of the main reasons for wanting a 6" screen is "fits in women's jacket pocket." (People who aren't familiar with the pockets issue in women's fashion will not know how to make reasonable suggestions.) But it's not clear from the reviews if there's page-turning buttons. (Maybe has only one button? Which can be set to different things for single click vs double click? But there's no list of the actual options that I could find.)
The $400 price tag (...possibly +$50 shipping?) is not as much a barrier as the fact that it doesn't seem to have any US storefront or tech support. (The Hisense A5... phone? which is an older model might work. But again: No reliable US source, no tech support.)
I'm aware that wanting buttons sharply limits my options. I used to have a Kobo Mini, which was touchscreen only, and when the battery started to run low, the screen didn't always register taps, which got really annoying. (Especially since the battery indicator also didn't work, so I didn't have any warning that it was low.)
And I hated having to constantly move my hand (or at least my finger) back and forth - move it onto the page to tap for next, and out of the way so I could read the text.
If a touchscreen-only reader had other features I really liked - that I haven't mentioned here, because it's hard to talk about navigation & sorting options - I might consider giving up page buttons. But an ereader would to offer better software functions that I'm getting from my current Pocketbook.
Things I'd like:
- Show filenames and sort by date/time added
- Edit metadata (hah; I don't think anything will let me edit the visible title)
- Show list (titles, authors, filenames) excluding books marked "complete"
- Select multiple ebooks & add them to categories/move them to folders
I'm aware Calibre would let me do most of that; I'm trying to dodge having to spend extra time sorting and then upload to the device. (I want to not have to get out of bed & start up the computer in order to sort ebooks to find the one(s) I want to read next.)