A couple days ago there was the Raspberry Pi Zero W announced.
It sells for $10.
$10 freaking dollars.
You get a computer that runs Linux and has wireless connectivity, and HDMI (mini) and USB and it can actually do stuff.
And it’s only $10.
Takes all of three main chips to pull it off. From looking at the layout the big chip is the processor and everything else. The little rectangle with no pins is the WiFi controller (which you can tell by the nice controlled impedance trace coming from it with the nice curves. The SOIC12 on the right is very likely a DC-DC converter based on the proximity to the inductor and capacitors.
And the other side has nothing.
A single sided load.