If you were on a mission to make the cheapest possible mobile phone, you would probably not do much better than Intex Cloud Fx. Running Firefox OS, it will cost users about $35 to purchase it outright. Its goal is to bring the internet to places which would otherwise have nothing.
I believe the largest concession made by this phone is its RAM — 128 MB. Yes, I had a computer with 32 MB of RAM and it browsed the internet just fine (on Netscape Navigator 2 through 4). I also had a computer before that (which was too slow to run Windows 3.1 but hey it had a turbo button). This is also the amount of RAM on the first and second generation iPod Touches. Nowadays, it is very little. Ars Technica allegedly made it crash by scrolling too fast and attempting to run benchmarks on it. This leads into its other, major compromise: its wireless connectivity. It does not support 3G. Edge is the best that you will get.
Other than those two points: it has a 1 GHz Spreadtrum SoC, 46MB of storage, a 2MP camera, and a 1250mAh battery. You do get WiFi, Bluetooth, and a microSD card slot. It also supports two SIM cards if necessary.
Again, at $35, this is not designed for America or Western Europe. This is for the areas of the world that will probably not experience the internet at all unless it is through a mobile phone. For people in India and Asia, it is about the lowest barrier to entry of the internet that is possible. You can also check out phones from other partners of Mozilla.