The largest discount you can find on a Surface book is on a refurb. The best place to get a refurb Surface Book is directly from Microsoft.
Brad's Deals Editor Michael,
Get a refurbished Microsoft Surface Book for $1,104 with free shipping at the Microsoft Store. This is the lowest price we could find for a refurbished unit by $45. This model has a 6th Gen Intel Core i5 processor, 8GB of memory, a detachable keyboard base, a 128GB solid-state drive, Windows 10, and more. Sales tax is charged in most states.