For keyboards, we can deal with refurbished or used. For storage, you are right, SDcard is the primary option, in a standalone product, it's not cheap (about 20%) comparing the total board price but we can find a more suitable formula if it will be included within the board. But the display will still a challenge if we choose to build custom board. HDMI TV are not such used in rural zones, they still need some time to be accessible in price and popularity.