If you've been planning to grab a 1TB Surface Book, it appears that you've missed the boat, as Microsoft has stopped selling the model on its online store. While they've been out of stock for some time, at one point there were two 1TB models, one with and one without a discrete GPU, with the latter showing up in March.
But now, the only option for a dGPU is the variant with a Core i5, 256GB of storage, and 8GB of RAM - which will cost you $1,899 - or the new Performance Base models, which were announced in October. In fact, all of the Surface Book with Performance Base models are still in stock, including the 1TB variant, which will run you $3,299.
But Microsoft's flagship convertible is showing its age, still using Intel's sixth-generation 'Skylake' processors. This puts the Book behind the new Surface Pro and Laptop, which both use seventh-generation 'Kaby Lake' processors.
According to Thurrott, the company may be planning a refresh for later on this year. This would be around the time that Intel's eighth-generation processors start showing up on the market, which will allow for quad-core U-series chips in ultrabooks.