Ebook readers use e-paper displays for two reasons. First is the innate nature of such screens, which are easy on the eyes and batteries. Second is the cheaper costs of such components, which translate to a more affordable retail price. If you thought the latter would be true of the Gvido music sheet "tablet" and its two 13-inch e-ink screens, you'd be shocked to find out the truth. Because when the Gvido launches later this year, it will cost just as much as two 12.9-inch iPad Pros.