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.
Inside is a 1GHz A31 quad-core processor from Allwinner Technology. That chip is based on the somewhat dated ARM Cortex A7 architecture.
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.
(Via Liliputing.)
To see what it's up against, check out our list of the best Android tablets on the market right now.