chubbiestech via eBay offers the Samsung Infuse 4G Android Smartphone for AT&T in Caviar Black, model no. i997, for $124.95 with free shipping. That's the lowest total price we could find by $29. Features include a 1.2GHz ARM Cortex-A8 processor, 4.5" 1280x720 Super AMOLED Plus touchscreen, 16GB internal storage, 8-megapixel rear-facing camera, 1.3-megapixel front-facing camera, 802.11n wireless, and Android 2.3.6 OS (Gingerbread).
Note: While this model is new, it was previously a store model.