What I would find interesting is if the guy who makes/sells the Giraud has made a killing on it.
From information on his site, he is a one man machine shop. He makes a couple of other things, like a folding target scope stand, and this business is a second job for him. He has a full time job as a design engineer.
I have no idea of the volume a one man machine shop can turn out, but it doesn't sound like a good way to get rich quick.
It sounds more like a guy who came up with the thing because he
wanted one, and then sells a few on the side to help support his shooting habit.