Also available is the Lenovo ThinkCentre M81 Intel Core i5 3.1GHz Desktop PC, model no. 7517C1U, for $598.18. Coupon code "DEALNEWS15" cuts it to $583.18. With free shipping, it's the lowest total price we could find by $20. It features an Intel Core i5-2400 3.1GHz Sandy Bridge dual-core processor, 4GB RAM, 500GB hard drive, DVD burner, Gigabit Ethernet, and Windows 7 Professional 64-bit.