I was going to explain that the only difference between the raspberry pi & generic pi is the support that comes from having the mindshare/marketshare. But honestly, I think in the scope of the real issue it's mostly bike-shedding.
If you want to deliver a million Pi to the subcontinent, the real problem isn't the dollar difference between the various SBC. If you compare a Pi to a phone, you also have to bring ..
- Power; not just the obvious, but also that the onboard battery on a phone brings a high tolerance for supply issues.
- Screen; preferably enough of a screen to make the outlay worth it. If you just put a phone screen on a pi, what did you really gain?
- Connectivity; particularly the last mile where the phone has near-infinite flexibility.
Of course none of these are remotely difficult (although connectivity can be difficult remotely), but they're all BOM cost that end up making the SBC one of the least interesting parts to solve. For most the Pi-based laptops & Tablets I've seen, the Pi itself is ballpark 10% of the overall cost.
I think if I was going to attempt this (and to be clear, I use that phrase entirely in the 'armchair quarterback' scope), I'd be trying to create a terminal that's essentially a phone dock - because this isn't going to be an either/or purchase, no-one's going to give up their phone to get this terminal instead. So instead of using all your BOM trying to recreate what they already have, concentrate on what they're missing.
