what i've learned from 5 yrs of ebay and gunbroker is how to spot trouble in questions. i always respond but there have been several people i've blocked as bidders just because of the question they asked or the way they asked them. not doing it for a living, i don't have to waste my time with anybody i don't want to.
i can well imagine the tone of a question implying something i listed was "bogus" and can guarantee the sender would never bid on anything of mine.
when i lived back east and would go to gun shows with my dad, there were regulars that i'd do no more than say hello to. they never bought anything, nitpicked everything, told me how much cheaper they could get it elsewhere, etcetc. i'd pick up a book and start reading till they'd finally show some sense and walk off. many gun buyers, i pity the dealers who, to make a living, have to put up with them.
roger