I just saw this on AA...I think you'll get a nice forearm/shoulder workout, but you could do that with regular handweights- or with a little creativity, some piping and a general understanding of welding and you could probably make your own for pennies on the dollar.
I know, I'm saying it, and we all know- I'm not doing that. Besides, I prefer that, if someone happens to look into my window, I be seen swinging a sword, and not a handle. Then I just look like I'm reliving various LARP fantasies. lol