Check out the the Bouffalo Labs BL808 or Sophon SG2000 series. They are a system-in-package products that contain a RISC-V CPU, RAM and flash memory all in a few mm square package, for a few dollars. Pine64 and Milk-V both have breakout boards for under $10.

They only have RAM and flash in the hundreds of megabytes, not gigabytes, but they can run full Linux and are as capable as many household Wi-Fi routers. They include USB, Bluetooth, Wi-Fi, and wired Ethernet ports, and even have MIPI CSI and DSI interfaces for cameras and displays.

The SG2000 is pretty interesting. I do wish they had gone with a more homogeneous architecture (4 identical cores like the pi 2 zero), and it's RVV 0.7, but the next generation of this could be really interesting.