It seems we have varying definitions of the same term.
My offers vary depending on how much I actually want the item. If it is something I really want and have been waiting for, I will offer a fair retail price off the bat. If it is something I'd kinda' like to have but waiting for a good deal, then the lower end of fair is what I'm shooting for...in other words, what it is worth to me. Now, if it is something I neither want or need, but it is kind of interesting and I might be able to trade it or make a buck at the next gun show, then my offer will be about half of what I think I can sell it for.
To me, "lowballing" is when it would be something really wanted, but offering a wholesale (or less) price. Happens all the time, but not in the case of the gent who offered these prices for your magnums.