Following the release of Windows 10 Insider build 17035 today, Microsoft announced that it’s finally possible to shop Surface hardware and accessories from the Microsoft Store app. To do it, you have to make sure that you’re running the Microsoft Store version 11709.1001.7 or higher. If you’re on the production ring or Release Preview Ring, you should be good to go.
You can try the new feature by clicking this link on a Windows 10 PC, though be aware that Surface hardware in the Microsoft Store is currently only available for U.S., U.K. and Australia markets:
Shopping Surface hardware and accessories from the Microsoft Store will give you the same benefits like free shipping and free returns as shopping from the store on the web. To help Microsoft improve the shopping experience, the Windows Insider team has created a new quest for the Feedback which you can check here. You don't need to purchase anything to complete the quest, in case you're wondering.