Today only and for My Best Buy members only, Best Buy offers the Microsoft Surface 3 128GB 10.8" Windows Tablet, model no. 7G6-00014, for $399.99 with free shipping. (Not a member? It's free to join.) That's the lowest total price we could find by $43 and tied with our mention from April as the best price we've seen. It features an Intel Atom Z8700 1.6GHz quad-core processor, 10.8" 1920x1280 LCD touch display, 4GB RAM, 128GB flash memory, 802.11ac wireless, Bluetooth 4.0, 3.5-megapixel front-facing camera, 8-megapixel rear-facing camera, and Windows 10.
Update: It's now available at this price for everyone through July 23.