My brother & I went in there once while we were going to the man-mall.
The guy didn't say shit, just stood in the corner glaring at us like we were the scum of the earth...
The whole time, I asked him questions, "Can I see that firearm?" Not a F(_)cking word came out of the guys mouth. For a moment he turned burning red I thought he was suffocating while choking on a male appendage that got lodged in his throat or something!
Then my brother asks, "Can I see that handgun?" He didn't say shit. My brother pulls out a big rolled wad of twenties. The guy walks toward him, smiles, "Sure... Which one..." my brother flipped him the bird put his money away and we walked out. When outside he said, that guy lost any chance at my money 30 seconds after we entered that store.
Now my brother is a die-hard GunStop advocate (he just wishes it was closer though).