The cost of building such a network is small.
The display is small, larger displays available from $22
- HooToo wireless travel router only $17.99 https://www.amazon.com/TP-LINK-TL-WR703N...0083Z54P02.
- battery - $15.99 https://www.amazon.com/Walkera-Airplane-...00HE6GQRY3.
- solar charger - $14.99 http://www.tmart.com/30000mAh-Dual-USB-I...0941.html4.
- chip computer $9.00
- Small color TFT display - $7.52 https://www.crystalfontz.com/product/cfa...lay-module
The display is small, larger displays available from $22