B&H Photo Video offers the MSI Z170 Krait Gaming 3X LGA 1151 ATX Motherboard for $129.99 with free shipping. That's the lowest total price we could find by $20, except for the mention below. It supports sixth-generation Intel Core i3/i5/i7 and Intel Pentium and Celeron processors and features DDR4 boost, three PCI-Express 3.0 x16 slots, three PCI Express x16 slots, four PCI Express 3.0 x1 slots, four USB 3.1 ports, two USB 2.0 ports, an HDMI port, an M.2 port, and six serial ATA 6Gb/s ports.

Note: Newegg has it for the same price with $2.99 for shipping.