If it would sell, they wouldn't have stopped making electronic typewriters. They wouldn't be anything other than crippled computers anyway. These days, I'd guess that most authors use a laptop PC. Why not just get a low cost laptop or AIO PC and install MS Word, Libre Writer or your favorite book writing software. Then configure it to run the word processing software when it starts up. Then add a cheap monochrome laser printer for printing. Tiny, portable printers are also available but I would't recommend using one.
Laptops are a lot more practical than an electronic typewriter when it comes to usability and portability. They are a small fraction of the size and weight of any typewriter, have a much better display, store more work and don't waste as much paper. In addition, the word processor can be easily updated or upgraded to something better.