"Low-end" presumably refers to the fact that it's resold graylabel hardware. I wouldn't be surprised if the unit manufacturing cost was below $50.

For $850 I'll sell you a couple of candybar Nokias with prepaid SIMs, and an afternoon's tuition on how to do one-time pads properly.

Hell, I'll do it for $425. If you bring your own phones, I'll do it for a chilli burger.