It's still 3x as expensive as an LCD display of the same size. The LCD display has full color, too.[1] The E-Ink display offers only 7 faded colors.
[1] https://www.buydisplay.com/5-inch-lcd-screen-tft-module-800x...
[1] https://www.buydisplay.com/5-inch-lcd-screen-tft-module-800x...