Make sure you have good and i mean really good phone contact information on this guy.
Last year i saw about 75 auctions on GB where the seller had no feedback and i noticed that he was selling Glock 27's with no reserve for a starting bid of $250.00 and some sigs for around the same thing,you could lose your ass with that many guns at no reserve and i contacted GB and asked them about the seller,he had a mail box at one of those mail drop places and things just looked screwy to me.
GB never got back to me ,i was able to contact some of the bidders and found out they were waiting and waiting for their guns some 6 weeks already,i then contacted the police in the town that he said he was from and they tracked him down and it was a big scam,when they seized his mail box there was another 25 money orders in it and he was about to skip town, after that is when GB put their fraud protection into affect.
I tried asking questions in their forums about it and the posts were deleted right away and i was e-mailed and told that posts "like mine" were not allowed.
I don't usually blow the whistle on anyone but i could not stand by and let people lose their money like that.