I had an AUG .223 (paid about £1000 or just under for the standard rifle circa 2013/2014). Low Mill Ranges (http://lowmillranges.co.uk/) did all the needed upgrades (Trigger Tamer, extended charging handle, barrel release button, etc.). I part exchanged it for a Remington 700 .223 in an MDT chassis. I received about £900 for the rifle including all the upgrades, moderator, magazines, etc, as a part exchange.