Sam Rutherford for Engadget If you were intrigued by ROG and Xreal's gaming AR headset at CES , you'll soon be able to get your hands on them for a hefty $849. ASUS's gaming subsidiary announced today that the ROG Xreal R1 glasses are now available for pre-order at Best Buy, and they'll also be sold from the company's website on May 17. We expected them to come in a bit higher than Xreal”s excellent $649 One Pro glasses , as the ROG model is essentially a supercharged upgrade, with a smoother 240Hz refresh rate and a bundled dock that makes it easy to plug in multiple consoles, PCs and other hardware. Otherwise, the Xreal R1 are pretty similar to Xreal's previous flagship hardware. They still have a 57-degree field of view, which is enough to create a 171-inch virtual screen from four meters away, and they're still running at 1080p.…