I believe there is no such thing, because an ebook-reader with just a 300ppi display and nothing else does not make a lot of sense.

The "chinese companies" mostly concentrate on android based devices, which are often a bit more expensive actually.
Also the price is not necessarily dictated by the included hardware. Cheapest option should be the Paperwhite (4), because Amazon often sells them at a loss (or without profit).
Or you could try to get a used one. Maybe an older model, like your Glo HD or a Paperwhite 3.