I think Pine64 is right on target here. The price is low to focus on getting a device quickly to the public for exposure and to get development/interest started. This is exactly what they should be focused on unlike the other company that has better specs, but the price is insane and they still have yet to ship a unit.

I also like the idea of being able to keep the frame of the phone and bring able to swap out the main board out with a better/newer one in the future. This itself is a great feature because accessories like a keyboard case and screen protectors can be retained. Also, with the cameras bring modular there could be an option to use camera combinations the user wants, being that the soc can support the cam.

Having a screen resolution of 720p is also smart because personally anything larger on a small screen is pointless and wastes battery power. If you need something bigger, plug in a monitor. I think they are on to something here.