Go look at one of the bidders. I think one was a shill bidder, in place to drive up the total sale price. One thing I do not like about GunBroker is the never ending extension they impose, to keep the auction going, as the price soars after what was the original end of auction time. I have seen too many auctions where the price gets driven up over and over again by bidders with few feed backs over literally years or decades of use. If I am interested in a item I just bid my top amount and let it go. Not willing to bid hundreds extra just because someone else does. If you have the time, you can trace a shill bidder because they will show up on other sales from the same seller. You will notice they will bid several time, at the end, but always seem to come up just short of the final winning bid. One shill bidder I discovered bid almost fifty times, in a month period, with zero wins and always for the same seller. When I brought this to GunBrokers attention they were not aware or concerned about it. That fake bidder was still playing his games a few month later on another item for the same seller. So GunBroker just does not care and did nothing.
I hope this works out well for the buyer. I expect they will find that GunBroker will be their usual absolutely worthless in resolving this issue. I have been forced to use credit card companies, Postal Inspectors, LEO and even had help from the BATF once. And PayPal is worse than GunBroker in my experience which is why I no longer use them for anything more than sending grand kids a few dollars for birthdays. And I do not think a "disclaimer" will absolve the seller from fraud ,which is what this type of deception is.