The $12 "Gongkai" Phone

Recently, I paid $12 at Mingtong Digital Mall for a complete phone, featuring quad-band GSM, Bluetooth, MP3 playback, and an OLED display plus keypad for the UI. Simple, but functional; nothing compared to a smartphone, but useful if you're going out and worried about getting your primary phone wet or stolen. [...] How is this possible? I don't have the answers, but it's something I'm trying to learn. A teardown yields a few hints.

These are amazing products for a specific niche, and the young teenager in me who got his first cellphone at 13 marvels at the price of this thing.