Sears offers the ZTE Merit Android Net10 Prepaid Phone, model no. NTZEZ768GP5, for $19.99. Plus, Shop Your Way Max members bag free shipping. (Not a member? It's free to sign up for a 90-day trial; otherwise, shipping adds $5.99. In-store pickup is also available.) That's the lowest total price we could find by $8. It features a 3.5" touchscreen, 3-megapixel camera, Bluetooth, 3G, WiFi, and Android 2.3 OS (Gingerbread).
zte_us via eBay offers the Unlocked ZTE Open 256MB Firefox OS Smartphone in Orange for $69.99 with free shipping. (Multi-Function1002 via eBay charges the same.) That's $10 under our September mention and the lowest total price we could find by $29. It features a 3.5" 320x480 touchscreen display, 1GHz Cortex-A5 processor, 256MB RAM, 512MB memory, 2-megapixel rear camera, accelerometer, Bluetooth 2.1, WiFi, and Firefox OS.