Thoughts on value for a Windham manufactured Bushmaster xm15. It has a little wear but overall in good shape. Upgraded with the following AAC 51 tooth threaded flash hider ready for your suppressor, knights armament rail with sliding locking covers, yankee hill machine flip up front sight integrated into gas block, magpul grip, magpul bad lever, mst minimalist stock, extended safety switch, upgraded trigger...I believe it is an American Trigger Corporation gold trigger. Im also pretty sure it has a FailZero BCG...but not positive on that. Can also throw in the magpul AFG. Ideas on value for this gem?