Since a year or so, Microsoft and Qualcomm are working together to bring Windows 10 on ARM with better app support, which is the major priority for the Redmond giant. This started after Microsoft partnered up with Qualcomm to develop a custom ARM processor called Snapdragon SQ1 which is the first ARM processor for the mainstream laptop market. The major issue after the launch was the app compatibility. Since x86-64 instruction based apps cannot run on ARM, because of completely different architecture, the number of apps are limited.
Now after a year, Qualcomm has finally developed a Developer Kit for the developers to get a cheaper solution to test and optimize their apps for the platform. For the specifications, you will get the 8nm Qualcomm 7c processor which has Kryo 468, along with X15 LTE modem, and support for QHD display @60Hz.
As of now, the price is not known, but it will definitely be a cheaper solution for developers instead of buying a full-fledged Surface Pro X just to test apps. Very soon, the Developer Kit will be available from Microsoft Store to purchase.