Quad-core doesn't get much cheaper than this.
That would be the $99.99 HP 7 Plus, which is now available in the US market, after debuting in Europe a few months ago.
So don't expect the fastest mobile processor on the planet, but it gets the job done for $100.
Other specs for the Hewlett-Packard tablet include the Android 4.2.2 Jelly Bean operating system, 1 GB of SDRAM, 8 GB of storage (eMMC), 802.11b/g/n Wi-Fi, over 5 hours of battery life, a microSD slot, and a 7-inch diagonal IPS 1,024 x 600 display.
HP also sells the $150 Slate 7 based on a quad-core Nvidia Tegra 3 processor.