@livedealer_fan Do it mate. Seriously. Reading back through this thread has reminded me why I made that decision 2 years ago.
To answer my own original question - yes, it was absolutely worth it. The temptation from non-Gamstop sites will always be there, but having that barrier in place for 90% of the market makes all the difference.
Cheers to everyone who shared their stories. Proper helpful stuff.