Dell Small Business & Home Office offers the Dell OptiPlex 390 Intel Core i5 3.1GHz Mini Tower Desktop PC (no monitor) for $549. Coupon code "7RZXPX9M7$JLVR" cuts it to $499. With free shipping, that's $415 off and tied with our mention from last week as the lowest total price we've seen for a Core i5-equipped Dell OptiPlex 390 with 4GB RAM. Sales tax is added where applicable. Features include an Intel Core i5-2400 3.1GHz Sandy Bridge quad-core processor, 4GB RAM, 500GB hard drive, DVD-ROM, Gigabit Ethernet, and Windows 7 Home Premium 64-bit. Deal ends September 30.