Maybe in material alone but the labor costs in cutting, sharpening and honing that steel sheet stock into the blade is gonna run at least another couple hundred in labor at a first guess. I also seriously doubt 16g steel is going to have the heft needed for an effective blade of that type.
Name of the game is efficiency and if you’re having to do multiple runs or add extra weight to the blade mechanism it just slows things down.
I see your point, but yes. The French method was created specifically as a means of efficiently and reliably getting the job done without having to rely on the skill of an executioner.
If a vengeful display is what you’re after there are better methods suited to that goal.