Great news, the Ring Alarm is coming to the UK in Early November. There is not price on the site yet, so it will be interesting to see where they pitch it. There seems to be a few differences for us with the main 2 being the lack of Full professional monitoring that includes emergency service contact - which was expected, and that Protect Plus is optional (Plus plan offers additioanl Assited Monitoring and Cellular backup features).
5 Piece set is £249 ($320) Includes Base Station, Keypad, Contact Sensor, Motion Detector and Range Extender. Currently the same set in the US is $199, so allowing for tax, the extra z-wave certification and the reduction in service level it should really be no more that £200 in the UK. I may wait a bit to see if there is any reduction or other sets available after launch.