£900 is about right because it is a wireless system but i would steer clear of ADT because they charge premium rate calls to the ARC everytime the alarm is set, unset or goes off.
Try approved local companies if you want a monitored system as they usually use well known and tested brands rather than in-house brands as used ny ADT and British Gas.
Ideally you should try to get a wired system or at least part wired as wireless can cause problems.
Try approved local companies if you want a monitored system as they usually use well known and tested brands rather than in-house brands as used ny ADT and British Gas.
Ideally you should try to get a wired system or at least part wired as wireless can cause problems.