...when I asked the guys if he had a case of them shipped in, he said "No, just that one.".
It's all about "real estate".
That one item is not cost effiecient to keep on the shelf. that case collecting dust could easily be replaced by a case of 1900 boxes that actually "move".
I have the same issue in my shop...sure I'd love to keep all sorts of stuff "on hand", but space is limited and what gets used most is what's stocked. I cannot justify the "expense" of keeping "non-standard" items on the shelf.