Walmart offers the refurbished HP 8000 Intel Core 2 Duo 3GHz Small Form Factor Desktop PC (no monitor) in Black, model no. 62805557110, for $139 with free shipping. That's $20 off and the lowest total price we could find for this configuration. Features include an Intel Core 2 Duo 3GHz dual-core processor, 8GB RAM, 1TB hard drive, DVD-ROM, Gigabit Ethernet, DisplayPort, USB, and Windows 10 Home 64-bit.
Note: A 1-year warranty applies, but it's unclear who covers it.