Bomber, you are doing the right thing! Keep sounding the alarm anytime you see these thieves and they ARE thieves. GB will not take their ads down even when you report them and at least one or two innocent people get robbed by these thieves. A deal that is too good to be true usually is not true, new sellers with no feed back should be handled carefully. I asked one to take the gun to a local FFL which he did and we handled the transaction via the FFL. Choose an FFL with a web site and business location. If a new seller won't do that walk away!
There is an old saying "all that is necessary for evil to prevail is for good men to do nothing". You stay on track brother! You are doing the right thing!