Looks like the Basic 3 is being replaced with the Basic 4 (which looks like the Lux Basic 2). If GoodERead has the correct information, the new Basic 4 will use a 212 ppi screen and will be very light – only 145 grams. One thing I don't like is that it will only have an 800 mAh battery instead of the 1300 mAh one in the Basic 3. I actually kind of like the old case, it was easy to hold.
GoodEReader is the only source I have for this but it looks legitimate...
https://goodereader.com/blog/product/pocketbook-basic-4
https://goodereader.com/blog/electro...available-soon